On Mon Oct 12, 2026 at 10:16 PM PDT, Hongtao Liu wrote:
> On Mon Oct 12, 2026 at 9:26 AM PDT, Shreesh Adiga wrote:
>> On Mon, Oct 12, 2026 at 12:45 PM Hongtao Liu <[email protected]> wrote:
>>
>>> On Sat Oct 10, 2026 at 9:52 AM PDT, Shreesh Adiga wrote:
>>> > From: Mariam Arutunian <[email protected]>
>>> >
>>> > This patch introduces pclmul expanders for the i386 backend,
>>> > dedicated to generating optimized code for CRC computations.
>>> >
>>> > Expander 1: Bit-Forward CRC (crc<SWI1248x:mode><SWI124:mode>4)
>>> > For targets that support both pclmulqdq instruction (TARGET_PCLMUL) and
>>> are
>>> > 64-bit (TARGET_64BIT),
>>> > the expander will generate code that uses the pclmulqdq instruction for
>>> CRC
>>> > computation.
>>> >
>>> > Expander 2: Bit-Reversed CRC (crc_rev<SWI1248x:mode><SWI124:mode>4)
>>> > If the target does not support crc32 but supports pclmulqdq, it then uses
>>> > the pclmulqdq instruction for bit-reversed CRC computation.
>>> >
>>> > This makes the x86 backend similar to aarch64 which uses pmull.
>>> >
>>> > gcc/ChangeLog:
>>> >
>>> > * config/i386/i386-expand.cc (ix86_expand_crc_using_pclmul): New
>>> > function that implements pclmul expansion for Bit-Forward CRC
>>> > computation.
>>> > (ix86_expand_reversed_crc_using_pclmul): New function that
>>> > implements pclmul expansion for Bit-Reversed CRC computation.
>>> > * config/i386/i386-protos.h (ix86_expand_crc_using_pclmul): New
>>> > extern function declaration.
>>> > (ix86_expand_reversed_crc_using_pclmul): Likewise.
>>> > * config/i386/i386.md (crc_rev<SWI124:mode>si4): Removed older
>>> > expansion for Bit-Reversed CRC.
>>> > (crc<SWI1248x:mode><SWI124:mode>4): Added new expander for
>>> > Bit-Forward CRC.
>>> > (crc_rev<SWI1248x:mode><SWI124:mode>4): Added new expander for
>>> > Bit-Reversed CRC which extends previous CRC32 expansion.
>>> >
>>> > gcc/testsuite/ChangeLog:
>>> >
>>> > * gcc.target/i386/crc-1-pclmul.c: New test.
>>> > * gcc.target/i386/crc-10-pclmul.c: New test.
>>> > * gcc.target/i386/crc-12-pclmul.c: New test.
>>> > * gcc.target/i386/crc-13-pclmul.c: New test.
>>> > * gcc.target/i386/crc-14-pclmul.c: New test.
>>> > * gcc.target/i386/crc-17-pclmul.c: New test.
>>> > * gcc.target/i386/crc-18-pclmul.c: New test.
>>> > * gcc.target/i386/crc-21-pclmul.c: New test.
>>> > * gcc.target/i386/crc-22-pclmul.c: New test.
>>> > * gcc.target/i386/crc-23-pclmul.c: New test.
>>> > * gcc.target/i386/crc-4-pclmul.c: New test.
>>> > * gcc.target/i386/crc-5-pclmul.c: New test.
>>> > * gcc.target/i386/crc-6-pclmul.c: New test.
>>> > * gcc.target/i386/crc-7-pclmul.c: New test.
>>> > * gcc.target/i386/crc-8-pclmul.c: New test.
>>> > * gcc.target/i386/crc-9-pclmul.c: New test.
>>> > * gcc.target/i386/crc-CCIT-data16-pclmul.c: New test.
>>> > * gcc.target/i386/crc-CCIT-data8-pclmul.c: New test.
>>> > * gcc.target/i386/crc-coremark-16bitdata-pclmul.c: New test.
>>> > * gcc.target/i386/crc-crc32-data16.c: New test.
>>> > * gcc.target/i386/crc-crc32-data32.c: New test.
>>> > * gcc.target/i386/crc-crc32-data8.c: New test.
>>> >
>>> > Co-authored-by: Shreesh Adiga <[email protected]>
>>> > Signed-off-by: Mariam Arutunian <[email protected]>
>>> > Signed-off-by: Shreesh Adiga <[email protected]>
>>> > ---
>>> > Changes in v2:
>>> > Replaced movabs + movq of quotient and polynomial with a single
>>> > 16 byte load and operate on different lanes of it with pclmul
>>> > selector argument.
>>> > Formatted i386.md changes to remove constraint and comments
>>> > after operand as per suggestion.
>>> > Added missing newline in the tests.
>>> >
>>> > gcc/config/i386/i386-expand.cc | 131 ++++++++++++++++++
>>> > gcc/config/i386/i386-protos.h | 3 +
>>> > gcc/config/i386/i386.md | 46 ++++--
>>> > gcc/testsuite/gcc.target/i386/crc-1-pclmul.c | 8 ++
>>> > gcc/testsuite/gcc.target/i386/crc-10-pclmul.c | 8 ++
>>> > gcc/testsuite/gcc.target/i386/crc-12-pclmul.c | 9 ++
>>> > gcc/testsuite/gcc.target/i386/crc-13-pclmul.c | 8 ++
>>> > gcc/testsuite/gcc.target/i386/crc-14-pclmul.c | 8 ++
>>> > gcc/testsuite/gcc.target/i386/crc-17-pclmul.c | 8 ++
>>> > gcc/testsuite/gcc.target/i386/crc-18-pclmul.c | 8 ++
>>> > gcc/testsuite/gcc.target/i386/crc-21-pclmul.c | 8 ++
>>> > gcc/testsuite/gcc.target/i386/crc-22-pclmul.c | 8 ++
>>> > gcc/testsuite/gcc.target/i386/crc-23-pclmul.c | 8 ++
>>> > gcc/testsuite/gcc.target/i386/crc-4-pclmul.c | 8 ++
>>> > gcc/testsuite/gcc.target/i386/crc-5-pclmul.c | 9 ++
>>> > gcc/testsuite/gcc.target/i386/crc-6-pclmul.c | 8 ++
>>> > gcc/testsuite/gcc.target/i386/crc-7-pclmul.c | 8 ++
>>> > gcc/testsuite/gcc.target/i386/crc-8-pclmul.c | 8 ++
>>> > gcc/testsuite/gcc.target/i386/crc-9-pclmul.c | 8 ++
>>> > .../gcc.target/i386/crc-CCIT-data16-pclmul.c | 9 ++
>>> > .../gcc.target/i386/crc-CCIT-data8-pclmul.c | 9 ++
>>> > .../i386/crc-coremark-16bitdata-pclmul.c | 9 ++
>>> > .../gcc.target/i386/crc-crc32-data16.c | 53 +++++++
>>> > .../gcc.target/i386/crc-crc32-data32.c | 53 +++++++
>>> > .../gcc.target/i386/crc-crc32-data8.c | 53 +++++++
>>> > 25 files changed, 483 insertions(+), 13 deletions(-)
>>> > create mode 100644 gcc/testsuite/gcc.target/i386/crc-1-pclmul.c
>>> > create mode 100644 gcc/testsuite/gcc.target/i386/crc-10-pclmul.c
>>> > create mode 100644 gcc/testsuite/gcc.target/i386/crc-12-pclmul.c
>>> > create mode 100644 gcc/testsuite/gcc.target/i386/crc-13-pclmul.c
>>> > create mode 100644 gcc/testsuite/gcc.target/i386/crc-14-pclmul.c
>>> > create mode 100644 gcc/testsuite/gcc.target/i386/crc-17-pclmul.c
>>> > create mode 100644 gcc/testsuite/gcc.target/i386/crc-18-pclmul.c
>>> > create mode 100644 gcc/testsuite/gcc.target/i386/crc-21-pclmul.c
>>> > create mode 100644 gcc/testsuite/gcc.target/i386/crc-22-pclmul.c
>>> > create mode 100644 gcc/testsuite/gcc.target/i386/crc-23-pclmul.c
>>> > create mode 100644 gcc/testsuite/gcc.target/i386/crc-4-pclmul.c
>>> > create mode 100644 gcc/testsuite/gcc.target/i386/crc-5-pclmul.c
>>> > create mode 100644 gcc/testsuite/gcc.target/i386/crc-6-pclmul.c
>>> > create mode 100644 gcc/testsuite/gcc.target/i386/crc-7-pclmul.c
>>> > create mode 100644 gcc/testsuite/gcc.target/i386/crc-8-pclmul.c
>>> > create mode 100644 gcc/testsuite/gcc.target/i386/crc-9-pclmul.c
>>> > create mode 100644
>>> gcc/testsuite/gcc.target/i386/crc-CCIT-data16-pclmul.c
>>> > create mode 100644 gcc/testsuite/gcc.target/i386/crc-CCIT-data8-pclmul.c
>>> > create mode 100644
>>> gcc/testsuite/gcc.target/i386/crc-coremark-16bitdata-pclmul.c
>>> > create mode 100644 gcc/testsuite/gcc.target/i386/crc-crc32-data16.c
>>> > create mode 100644 gcc/testsuite/gcc.target/i386/crc-crc32-data32.c
>>> > create mode 100644 gcc/testsuite/gcc.target/i386/crc-crc32-data8.c
>>> >
>>> > diff --git a/gcc/config/i386/i386-expand.cc
>>> b/gcc/config/i386/i386-expand.cc
>>> > index fb4224af0da..f483a04dfe1 100644
>>> > --- a/gcc/config/i386/i386-expand.cc
>>> > +++ b/gcc/config/i386/i386-expand.cc
>>> > @@ -29917,4 +29917,135 @@ ix86_expand_lcp_stall_peephole (rtx_insn
>>> *insn, rtx *operands,
>>> > emit_insn (set);
>>> > }
>>> >
>>> > +/* Generate assembly to calculate CRC using pclmulqdq instruction.
>>> > + OPERANDS[1] is input CRC,
>>> > + OPERANDS[2] is data (message),
>>> > + OPERANDS[3] is the polynomial without the leading 1. */
>>> > +
>>> > +void
>>> > +ix86_expand_crc_using_pclmul (scalar_mode crc_mode,
>>> > + scalar_mode data_mode,
>>> > + rtx *operands)
>>> > +{
>>> > + /* Check and keep arguments. */
>>> > + gcc_assert (!CONST_INT_P (operands[0]));
>>> > + gcc_assert (CONST_INT_P (operands[3]));
>>> > + rtx crc = operands[1];
>>> > + rtx data = operands[2];
>>> > + rtx polynomial = operands[3];
>>> > +
>>> > + unsigned HOST_WIDE_INT crc_size = GET_MODE_BITSIZE (crc_mode);
>>> > + unsigned HOST_WIDE_INT data_size = GET_MODE_BITSIZE (data_mode);
>>> > + gcc_assert (crc_size <= 32);
>>> > + gcc_assert (data_size <= crc_size);
>>> > +
>>> > + /* Calculate the quotient. */
>>> > + unsigned HOST_WIDE_INT
>>> > + q = gf2n_poly_long_div_quotient (UINTVAL (polynomial), crc_size);
>>> > +
>>> > + if (crc_size > data_size)
>>> > + crc = expand_shift (RSHIFT_EXPR, DImode, crc, crc_size - data_size,
>>> > + NULL_RTX, 1);
>>> > +
>>> > + /* Keep the quotient and polynomial in V2DImode. */
>>> > + rtvec q_poly_constants = gen_rtvec (2, gen_int_mode (q, DImode),
>>> > + gen_int_mode (UINTVAL (polynomial),
>>> > + DImode));
>>> > + rtx constants_v2di = gen_rtx_CONST_VECTOR (V2DImode,
>>> q_poly_constants);
>>> > + rtx constants_mem = validize_mem (force_const_mem (V2DImode,
>>> constants_v2di));
>>> > + rtx constants_reg = gen_reg_rtx (V2DImode);
>>> > + emit_move_insn (constants_reg, constants_mem);
>>> > +
>>> > + /* crc ^ data and keep in V2DImode. */
>>> > + rtx cd_xor = expand_binop (DImode, xor_optab, crc, data, NULL_RTX, 1,
>>> > + OPTAB_WIDEN);
>>> > + rtx res = gen_reg_rtx (V2DImode);
>>> > + emit_insn (gen_vec_concatv2di (res, cd_xor, const0_rtx));
>>> > + /* Perform carry-less multiplication with quotient. */
>>> > + emit_insn (gen_pclmulqdq (res, res, constants_reg, const0_rtx));
>>> > +
>>> > + res = expand_shift (RSHIFT_EXPR, V2DImode, res, crc_size, NULL_RTX,
>>> 1);
>>> > +
>>> > + /* Perform carry-less multiplication with polynomial and get low
>>> part. */
>>> > + emit_insn (gen_pclmulqdq (res, res, constants_reg,
>>> > + gen_int_mode (0x10, SImode)));
>>> > + rtx crc_part = gen_reg_rtx (DImode);
>>> > + emit_insn (gen_vec_extractv2didi (crc_part, res, const0_rtx));
>>> > +
>>> > + if (crc_size > data_size)
>>> > + {
>>> > + rtx shift = expand_shift (LSHIFT_EXPR, DImode, operands[1],
>>> data_size,
>>> > + NULL_RTX, 1);
>>> > + crc_part = expand_binop (DImode, xor_optab, crc_part, shift,
>>> NULL_RTX, 1,
>>> > + OPTAB_DIRECT);
>>> > + }
>>> > + emit_move_insn (operands[0], gen_lowpart (crc_mode, crc_part));
>>> > +}
>>> > +
>>> > +/* Generate assembly to calculate reversed CRC using pclmulqdq
>>> instruction.
>>> > + OPERANDS[1] is input CRC,
>>> > + OPERANDS[2] is data (message),
>>> > + OPERANDS[3] is the polynomial without the leading 1. */
>>> > +
>>> > +void
>>> > +ix86_expand_reversed_crc_using_pclmul (scalar_mode crc_mode,
>>> > + scalar_mode data_mode,
>>> > + rtx *operands)
>>> > +{
>>> > + /* Check and keep arguments. */
>>> > + gcc_assert (!CONST_INT_P (operands[0]));
>>> > + gcc_assert (CONST_INT_P (operands[3]));
>>> > + rtx crc = operands[1];
>>> > + rtx data = operands[2];
>>> > + rtx polynomial = operands[3];
>>> > +
>>> > + unsigned HOST_WIDE_INT crc_size = GET_MODE_BITSIZE (crc_mode);
>>> > + unsigned HOST_WIDE_INT data_size = GET_MODE_BITSIZE (data_mode);
>>> > + gcc_assert (crc_size <= 32);
>>> > + gcc_assert (data_size <= crc_size);
>>> > +
>>> > + /* Calculate the quotient. */
>>> > + unsigned HOST_WIDE_INT
>>> > + q = gf2n_poly_long_div_quotient (UINTVAL (polynomial), crc_size);
>>> > + /* Reflect the calculated quotient. */
>>> > + q = reflect_hwi (q, crc_size + 1);
>>> > +
>>> > + unsigned HOST_WIDE_INT reflected_op3 = reflect_hwi (UINTVAL
>>> (polynomial),
>>> > + crc_size);
>>> > + /* Keep the quotient and reflected polynomial in V2DImode. */
>>> > + rtvec q_poly_constants = gen_rtvec (2, gen_int_mode (q, DImode),
>>> > + gen_int_mode (reflected_op3 << 1,
>>> > + DImode));
>>> > + rtx constants_v2di = gen_rtx_CONST_VECTOR (V2DImode,
>>> q_poly_constants);
>>> > + rtx constants_mem = validize_mem (force_const_mem (V2DImode,
>>> constants_v2di));
>>> > + rtx constants_reg = gen_reg_rtx (V2DImode);
>>> > + emit_move_insn (constants_reg, constants_mem);
>>> > +
>>> > + /* crc ^ data and keep in V2DImode. */
>>> > + rtx cd_xor = expand_binop (DImode, xor_optab, crc, data, NULL_RTX, 1,
>>> > + OPTAB_WIDEN);
>>> > +
>>> > + /* Perform carry-less multiplication with quotient. */
>>> > + rtx res = gen_reg_rtx (V2DImode);
>>> > + emit_insn (gen_vec_concatv2di (res, cd_xor, const0_rtx));
>>> > + emit_insn (gen_pclmulqdq (res, res, constants_reg, const0_rtx));
>>> > +
>>> > + res = expand_shift (LSHIFT_EXPR, V2DImode, res, 64 - data_size,
>>> NULL_RTX, 0);
>>> > +
>>> > + /* Perform carry-less multiplication with polynomial and get high
>>> part. */
>>> > + emit_insn (gen_pclmulqdq (res, res, constants_reg,
>>> > + gen_int_mode (0x10, SImode)));
>>> > + rtx res_high = gen_reg_rtx (DImode);
>>> > + emit_insn (gen_vec_extractv2didi (res_high, res, const1_rtx));
>>> > +
>>> > + if (crc_size > data_size)
>>> > + {
>>> > + rtx shift = expand_shift (RSHIFT_EXPR, DImode, crc, data_size,
>>> > + NULL_RTX, 1);
>>> > + res_high = expand_binop (DImode, xor_optab, res_high, shift,
>>> NULL_RTX, 1,
>>> > + OPTAB_DIRECT);
>>> > + }
>>> > + emit_move_insn (operands[0], gen_lowpart (crc_mode, res_high));
>>> > +}
>>> > +
>>> > #include "gt-i386-expand.h"
>>> > diff --git a/gcc/config/i386/i386-protos.h
>>> b/gcc/config/i386/i386-protos.h
>>> > index 21994d3d498..d225a8fadc2 100644
>>> > --- a/gcc/config/i386/i386-protos.h
>>> > +++ b/gcc/config/i386/i386-protos.h
>>> > @@ -449,3 +449,6 @@ extern void ix86_set_handled_components (sbitmap);
>>> > bool ix86_check_builtin_isa_match (unsigned int, HOST_WIDE_INT*,
>>> > HOST_WIDE_INT*);
>>> > rtx ix86_vgf2p8affine_shift_matrix (rtx, rtx, enum rtx_code);
>>> > +extern void ix86_expand_crc_using_pclmul (scalar_mode, scalar_mode, rtx
>>> *);
>>> > +extern void ix86_expand_reversed_crc_using_pclmul (scalar_mode,
>>> scalar_mode,
>>> > + rtx *);
>>> > diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
>>> > index 4e18797743f..d032c2269f4 100644
>>> > --- a/gcc/config/i386/i386.md
>>> > +++ b/gcc/config/i386/i386.md
>>> > @@ -30504,19 +30504,39 @@ (define_insn "sse4_2_crc32di"
>>> > (set_attr "prefix_extra" "1")
>>> > (set_attr "mode" "DI")])
>>> >
>>> > -(define_expand "crc_rev<SWI124:mode>si4"
>>> > - [(match_operand:SI 0 "register_operand")
>>> > - (match_operand:SI 1 "register_operand")
>>> > - (match_operand:SWI124 2 "nonimmediate_operand")
>>> > - (match_operand:SI 3 "const_int_operand")]
>>> > - "TARGET_CRC32"
>>> > -{
>>> > - /* crc32 uses iSCSI polynomial */
>>> > - if (INTVAL (operands[3]) == 0x1EDC6F41)
>>> > - emit_insn (gen_sse4_2_crc32<mode> (operands[0], operands[1],
>>> operands[2]));
>>> > - else
>>> > - expand_reversed_crc_table_based (operands[0], operands[1],
>>> operands[2],
>>> > - operands[3], <SWI124:MODE>mode);
>>> > +;; Bit-forward CRC
>>> > +(define_expand "crc<SWI1248x:mode><SWI124:mode>4"
>>> > + [(match_operand:SWI124 0 "register_operand") ;; return value
>>> (CRC)
>>> > + (match_operand:SWI124 1 "register_operand") ;; initial CRC
>>> > + (match_operand:SWI1248x 2 "register_operand") ;; data
>>> > + (match_operand:SWI124 3 "const_int_operand")] ;; polynomial
>>> > + "TARGET_64BIT && TARGET_PCLMUL
>>> > + && <SWI124:MODE>mode >= <SWI1248x:MODE>mode"
>>> I think pclmul benifts 16/32/64-bit but not 8-bit data?
>>>
>>>
>> It does save on the lookup table though. 32 bit CRC would use 2kB storage.
>> Do you suggest this should be skipped for 8-bit data?
> Yes.
>
>>
>>
>>> > +{
>>> > + ix86_expand_crc_using_pclmul (<SWI124:MODE>mode, <SWI1248x:MODE>mode,
>>> > + operands);
>>> > + DONE;
>>> > +})
>>> > +
>>> > +;; Reversed CRC
>>> > +(define_expand "crc_rev<SWI1248x:mode><SWI124:mode>4"
>>> > + [(match_operand:SWI124 0 "register_operand") ;; return value
>>> (CRC)
>>> > + (match_operand:SWI124 1 "register_operand") ;; initial CRC
>>> > + (match_operand:SWI1248x 2 "register_operand") ;; data
>>> > + (match_operand:SWI124 3 "const_int_operand")] ;; polynomial
>>> > + "<SWI124:MODE>mode >= <SWI1248x:MODE>mode"
>>> Should it be
>>> "<SWI124:MODE>mode >= <SWI1248x:MODE>mode
>>> && ((TARGET_64BIT && TARGET_PCLMUL)
>>> || (TARGET_CRC32 && <SWI124:MODE>mode == SImode))" ?
>>>
>>> Without an ISA test, crc_rev is now available on every x86 target.
>>> I think the purpose of the patch is to extend it with PCLMUL but not
>>> change other behaviors?
>>>
>>>
>> The else part is generic right? Is it necessary to have all the ISA tests
>> here?
>> I'm planning to remove the 64 bit check as this seems to also work for 32
>> bit as well.
> Yes else part is generic, but the existenece of the optab impacts the
> middle-end optimization decisions(it replaces bit loop with optab when it's
> available, but the body then emits the table which has bigger codesize than
> bit loop), I think that's why we have TARGET_CRC32 in the original crc_rev
> optab, so I think we probably should also keep TARGET_64BIT check instead of
> falling back to table solution.
Looks like the patch can generate pclmul solution for ia32 too, so removing
TARGET_64BIT won't fall back to table solution, and should be ok.
>>
>> Thanks,
>> Shreesh
>>
>>
>>> > + {
>>> > + /* If it is iSCSI polynomial (0x1EDC6F41), generate crc32
>>> instruction. */
>>> > + if (TARGET_CRC32 && INTVAL (operands[3]) == 0x1EDC6F41
>>> > + && <SWI124:MODE>mode == SImode)
>>> > + emit_insn (gen_sse4_2_crc32<SWI1248x:mode> (operands[0],
>>> operands[1],
>>> > + operands[2]));
>>> > + else if (TARGET_64BIT && TARGET_PCLMUL)
>>> > + ix86_expand_reversed_crc_using_pclmul (<SWI124:MODE>mode,
>>> > + <SWI1248x:MODE>mode,
>>> operands);
>>> > + else
>>> > + expand_reversed_crc_table_based (operands[0], operands[1],
>>> operands[2],
>>> > + operands[3], <SWI1248x:MODE>mode);
>>> > DONE;
>>> > })
>>> >
>>> > diff --git a/gcc/testsuite/gcc.target/i386/crc-1-pclmul.c
>>> b/gcc/testsuite/gcc.target/i386/crc-1-pclmul.c
>>> > new file mode 100644
>>> > index 00000000000..f423c08cf07
>>> > --- /dev/null
>>> > +++ b/gcc/testsuite/gcc.target/i386/crc-1-pclmul.c
>>> > @@ -0,0 +1,8 @@
>>> > +/* { dg-do run } */
>>> > +/* { dg-options "-mpclmul -O2 -fdump-rtl-dfinish -fdump-tree-crc
>>> -fdisable-tree-phiopt2 -fdisable-tree-phiopt3" } */
>>> > +
>>> > +#include "../../gcc.dg/torture/crc-1.c"
>>> > +
>>> > +/* { dg-final { scan-tree-dump "calculates CRC!" "crc"} } */
>>> > +/* { dg-final { scan-tree-dump-times "Couldn't generate faster CRC
>>> code." 0 "crc"} } */
>>> > +/* { dg-final { scan-rtl-dump "pclmulqdq" "dfinish"} } */
>>> > diff --git a/gcc/testsuite/gcc.target/i386/crc-10-pclmul.c
>>> b/gcc/testsuite/gcc.target/i386/crc-10-pclmul.c
>>> > new file mode 100644
>>> > index 00000000000..39bfd386d9c
>>> > --- /dev/null
>>> > +++ b/gcc/testsuite/gcc.target/i386/crc-10-pclmul.c
>>> > @@ -0,0 +1,8 @@
>>> > +/* { dg-do run } */
>>> > +/* { dg-options "-mpclmul -O2 -fdump-rtl-dfinish -fdump-tree-crc" } */
>>> > +
>>> > +#include "../../gcc.dg/torture/crc-10.c"
>>> > +
>>> > +/* { dg-final { scan-tree-dump "calculates CRC!" "crc"} } */
>>> > +/* { dg-final { scan-tree-dump-times "Couldn't generate faster CRC
>>> code." 0 "crc"} } */
>>> > +/* { dg-final { scan-rtl-dump "pclmulqdq" "dfinish"} } */
>>> > diff --git a/gcc/testsuite/gcc.target/i386/crc-12-pclmul.c
>>> b/gcc/testsuite/gcc.target/i386/crc-12-pclmul.c
>>> > new file mode 100644
>>> > index 00000000000..1ac9a6bf56d
>>> > --- /dev/null
>>> > +++ b/gcc/testsuite/gcc.target/i386/crc-12-pclmul.c
>>> > @@ -0,0 +1,9 @@
>>> > +/* { dg-do run } */
>>> > +/* { dg-options "-mpclmul -O2 -fdump-rtl-dfinish -fdump-tree-crc
>>> -fdisable-tree-phiopt2 -fdisable-tree-phiopt3" } */
>>> > +/* { dg-skip-if "" { *-*-* } { "-flto"} } */
>>> > +
>>> > +#include "../../gcc.dg/torture/crc-12.c"
>>> > +
>>> > +/* { dg-final { scan-tree-dump "calculates CRC!" "crc"} } */
>>> > +/* { dg-final { scan-tree-dump-times "Couldn't generate faster CRC
>>> code." 0 "crc"} } */
>>> > +/* { dg-final { scan-rtl-dump "pclmulqdq" "dfinish"} } */
>>> > diff --git a/gcc/testsuite/gcc.target/i386/crc-13-pclmul.c
>>> b/gcc/testsuite/gcc.target/i386/crc-13-pclmul.c
>>> > new file mode 100644
>>> > index 00000000000..c290539fad3
>>> > --- /dev/null
>>> > +++ b/gcc/testsuite/gcc.target/i386/crc-13-pclmul.c
>>> > @@ -0,0 +1,8 @@
>>> > +/* { dg-do run } */
>>> > +/* { dg-options "-mpclmul -O2 -fdump-rtl-dfinish -fdump-tree-crc" } */
>>> > +
>>> > +#include "../../gcc.dg/torture/crc-13.c"
>>> > +
>>> > +/* { dg-final { scan-tree-dump "calculates CRC!" "crc"} } */
>>> > +/* { dg-final { scan-tree-dump-times "Couldn't generate faster CRC
>>> code." 0 "crc"} } */
>>> > +/* { dg-final { scan-rtl-dump "pclmulqdq" "dfinish"} } */
>>> > diff --git a/gcc/testsuite/gcc.target/i386/crc-14-pclmul.c
>>> b/gcc/testsuite/gcc.target/i386/crc-14-pclmul.c
>>> > new file mode 100644
>>> > index 00000000000..cc62ee471c7
>>> > --- /dev/null
>>> > +++ b/gcc/testsuite/gcc.target/i386/crc-14-pclmul.c
>>> > @@ -0,0 +1,8 @@
>>> > +/* { dg-do run } */
>>> > +/* { dg-options "-mpclmul -O2 -fdump-rtl-dfinish -fdump-tree-crc" } */
>>> > +
>>> > +#include "../../gcc.dg/torture/crc-14.c"
>>> > +
>>> > +/* { dg-final { scan-tree-dump "calculates CRC!" "crc"} } */
>>> > +/* { dg-final { scan-tree-dump-times "Couldn't generate faster CRC
>>> code." 0 "crc"} } */
>>> > +/* { dg-final { scan-rtl-dump "pclmulqdq" "dfinish"} } */
>>> > diff --git a/gcc/testsuite/gcc.target/i386/crc-17-pclmul.c
>>> b/gcc/testsuite/gcc.target/i386/crc-17-pclmul.c
>>> > new file mode 100644
>>> > index 00000000000..660bff55e1b
>>> > --- /dev/null
>>> > +++ b/gcc/testsuite/gcc.target/i386/crc-17-pclmul.c
>>> > @@ -0,0 +1,8 @@
>>> > +/* { dg-do run } */
>>> > +/* { dg-options "-mpclmul -O2 -fdump-rtl-dfinish -fdump-tree-crc" } */
>>> > +
>>> > +#include "../../gcc.dg/torture/crc-17.c"
>>> > +
>>> > +/* { dg-final { scan-tree-dump "calculates CRC!" "crc"} } */
>>> > +/* { dg-final { scan-tree-dump-times "Couldn't generate faster CRC
>>> code." 0 "crc"} } */
>>> > +/* { dg-final { scan-rtl-dump "pclmulqdq" "dfinish"} } */
>>> > diff --git a/gcc/testsuite/gcc.target/i386/crc-18-pclmul.c
>>> b/gcc/testsuite/gcc.target/i386/crc-18-pclmul.c
>>> > new file mode 100644
>>> > index 00000000000..e54392b32a9
>>> > --- /dev/null
>>> > +++ b/gcc/testsuite/gcc.target/i386/crc-18-pclmul.c
>>> > @@ -0,0 +1,8 @@
>>> > +/* { dg-do run } */
>>> > +/* { dg-options "-mpclmul -O2 -fdump-rtl-dfinish -fdump-tree-crc" } */
>>> > +
>>> > +#include "../../gcc.dg/torture/crc-18.c"
>>> > +
>>> > +/* { dg-final { scan-tree-dump "calculates CRC!" "crc"} } */
>>> > +/* { dg-final { scan-tree-dump-times "Couldn't generate faster CRC
>>> code." 0 "crc"} } */
>>> > +/* { dg-final { scan-rtl-dump "pclmulqdq" "dfinish"} } */
>>> > diff --git a/gcc/testsuite/gcc.target/i386/crc-21-pclmul.c
>>> b/gcc/testsuite/gcc.target/i386/crc-21-pclmul.c
>>> > new file mode 100644
>>> > index 00000000000..4db1504cd49
>>> > --- /dev/null
>>> > +++ b/gcc/testsuite/gcc.target/i386/crc-21-pclmul.c
>>> > @@ -0,0 +1,8 @@
>>> > +/* { dg-do run } */
>>> > +/* { dg-options "-mpclmul -O2 -fdump-rtl-dfinish -fdump-tree-crc" } */
>>> > +
>>> > +#include "../../gcc.dg/torture/crc-21.c"
>>> > +
>>> > +/* { dg-final { scan-tree-dump "calculates CRC!" "crc"} } */
>>> > +/* { dg-final { scan-tree-dump-times "Couldn't generate faster CRC
>>> code." 0 "crc"} } */
>>> > +/* { dg-final { scan-rtl-dump "pclmulqdq" "dfinish"} } */
>>> > diff --git a/gcc/testsuite/gcc.target/i386/crc-22-pclmul.c
>>> b/gcc/testsuite/gcc.target/i386/crc-22-pclmul.c
>>> > new file mode 100644
>>> > index 00000000000..d0f27d96069
>>> > --- /dev/null
>>> > +++ b/gcc/testsuite/gcc.target/i386/crc-22-pclmul.c
>>> > @@ -0,0 +1,8 @@
>>> > +/* { dg-do run } */
>>> > +/* { dg-options "-mpclmul -O2 -fdump-rtl-dfinish -fdump-tree-crc" } */
>>> > +
>>> > +#include "../../gcc.dg/torture/crc-22.c"
>>> > +
>>> > +/* { dg-final { scan-tree-dump "calculates CRC!" "crc"} } */
>>> > +/* { dg-final { scan-tree-dump-times "Couldn't generate faster CRC
>>> code." 0 "crc"} } */
>>> > +/* { dg-final { scan-rtl-dump "pclmulqdq" "dfinish"} } */
>>> > diff --git a/gcc/testsuite/gcc.target/i386/crc-23-pclmul.c
>>> b/gcc/testsuite/gcc.target/i386/crc-23-pclmul.c
>>> > new file mode 100644
>>> > index 00000000000..666f3620597
>>> > --- /dev/null
>>> > +++ b/gcc/testsuite/gcc.target/i386/crc-23-pclmul.c
>>> > @@ -0,0 +1,8 @@
>>> > +/* { dg-do run } */
>>> > +/* { dg-options "-mpclmul -O2 -fdump-rtl-dfinish -fdump-tree-crc" } */
>>> > +
>>> > +#include "../../gcc.dg/torture/crc-23.c"
>>> > +
>>> > +/* { dg-final { scan-tree-dump "calculates CRC!" "crc"} } */
>>> > +/* { dg-final { scan-tree-dump-times "Couldn't generate faster CRC
>>> code." 0 "crc"} } */
>>> > +/* { dg-final { scan-rtl-dump "pclmulqdq" "dfinish"} } */
>>> > diff --git a/gcc/testsuite/gcc.target/i386/crc-4-pclmul.c
>>> b/gcc/testsuite/gcc.target/i386/crc-4-pclmul.c
>>> > new file mode 100644
>>> > index 00000000000..398ecaa4aba
>>> > --- /dev/null
>>> > +++ b/gcc/testsuite/gcc.target/i386/crc-4-pclmul.c
>>> > @@ -0,0 +1,8 @@
>>> > +/* { dg-do run } */
>>> > +/* { dg-options "-mpclmul -O2 -fdump-rtl-dfinish -fdump-tree-crc" } */
>>> > +
>>> > +#include "../../gcc.dg/torture/crc-4.c"
>>> > +
>>> > +/* { dg-final { scan-tree-dump "calculates CRC!" "crc"} } */
>>> > +/* { dg-final { scan-tree-dump-times "Couldn't generate faster CRC
>>> code." 0 "crc"} } */
>>> > +/* { dg-final { scan-rtl-dump "pclmulqdq" "dfinish"} } */
>>> > diff --git a/gcc/testsuite/gcc.target/i386/crc-5-pclmul.c
>>> b/gcc/testsuite/gcc.target/i386/crc-5-pclmul.c
>>> > new file mode 100644
>>> > index 00000000000..4b487fefd95
>>> > --- /dev/null
>>> > +++ b/gcc/testsuite/gcc.target/i386/crc-5-pclmul.c
>>> > @@ -0,0 +1,9 @@
>>> > +/* { dg-do run } */
>>> > +/* { dg-options "-mpclmul -O2 -w -fdump-rtl-dfinish -fdump-tree-crc" }
>>> */
>>> > +/* { dg-skip-if "" { *-*-* } { "-flto"} } */
>>> > +
>>> > +#include "../../gcc.dg/torture/crc-5.c"
>>> > +
>>> > +/* { dg-final { scan-tree-dump "calculates CRC!" "crc"} } */
>>> > +/* { dg-final { scan-tree-dump-times "Couldn't generate faster CRC
>>> code." 0 "crc"} } */
>>> > +/* { dg-final { scan-rtl-dump "pclmulqdq" "dfinish"} } */
>>> > diff --git a/gcc/testsuite/gcc.target/i386/crc-6-pclmul.c
>>> b/gcc/testsuite/gcc.target/i386/crc-6-pclmul.c
>>> > new file mode 100644
>>> > index 00000000000..614423039d4
>>> > --- /dev/null
>>> > +++ b/gcc/testsuite/gcc.target/i386/crc-6-pclmul.c
>>> > @@ -0,0 +1,8 @@
>>> > +/* { dg-do run } */
>>> > +/* { dg-options "-mpclmul -O2 -fdump-rtl-dfinish -fdump-tree-crc" } */
>>> > +
>>> > +#include "../../gcc.dg/torture/crc-6.c"
>>> > +
>>> > +/* { dg-final { scan-tree-dump "calculates CRC!" "crc"} } */
>>> > +/* { dg-final { scan-tree-dump-times "Couldn't generate faster CRC
>>> code." 0 "crc"} } */
>>> > +/* { dg-final { scan-rtl-dump "pclmulqdq" "dfinish"} } */
>>> > diff --git a/gcc/testsuite/gcc.target/i386/crc-7-pclmul.c
>>> b/gcc/testsuite/gcc.target/i386/crc-7-pclmul.c
>>> > new file mode 100644
>>> > index 00000000000..3e5cc75338e
>>> > --- /dev/null
>>> > +++ b/gcc/testsuite/gcc.target/i386/crc-7-pclmul.c
>>> > @@ -0,0 +1,8 @@
>>> > +/* { dg-do run } */
>>> > +/* { dg-options "-mpclmul -O2 -fdump-rtl-dfinish -fdump-tree-crc" } */
>>> > +
>>> > +#include "../../gcc.dg/torture/crc-7.c"
>>> > +
>>> > +/* { dg-final { scan-tree-dump "calculates CRC!" "crc"} } */
>>> > +/* { dg-final { scan-tree-dump-times "Couldn't generate faster CRC
>>> code." 0 "crc"} } */
>>> > +/* { dg-final { scan-rtl-dump "pclmulqdq" "dfinish"} } */
>>> > diff --git a/gcc/testsuite/gcc.target/i386/crc-8-pclmul.c
>>> b/gcc/testsuite/gcc.target/i386/crc-8-pclmul.c
>>> > new file mode 100644
>>> > index 00000000000..4b1145553fc
>>> > --- /dev/null
>>> > +++ b/gcc/testsuite/gcc.target/i386/crc-8-pclmul.c
>>> > @@ -0,0 +1,8 @@
>>> > +/* { dg-do run } */
>>> > +/* { dg-options "-mpclmul -O2 -fdump-rtl-dfinish -fdump-tree-crc" } */
>>> > +
>>> > +#include "../../gcc.dg/torture/crc-8.c"
>>> > +
>>> > +/* { dg-final { scan-tree-dump "calculates CRC!" "crc"} } */
>>> > +/* { dg-final { scan-tree-dump-times "Couldn't generate faster CRC
>>> code." 0 "crc"} } */
>>> > +/* { dg-final { scan-rtl-dump "pclmulqdq" "dfinish"} } */
>>> > diff --git a/gcc/testsuite/gcc.target/i386/crc-9-pclmul.c
>>> b/gcc/testsuite/gcc.target/i386/crc-9-pclmul.c
>>> > new file mode 100644
>>> > index 00000000000..204d6c84d47
>>> > --- /dev/null
>>> > +++ b/gcc/testsuite/gcc.target/i386/crc-9-pclmul.c
>>> > @@ -0,0 +1,8 @@
>>> > +/* { dg-do run } */
>>> > +/* { dg-options "-mpclmul -O2 -fdump-rtl-dfinish -fdump-tree-crc" } */
>>> > +
>>> > +#include "../../gcc.dg/torture/crc-9.c"
>>> > +
>>> > +/* { dg-final { scan-tree-dump "calculates CRC!" "crc"} } */
>>> > +/* { dg-final { scan-tree-dump-times "Couldn't generate faster CRC
>>> code." 0 "crc"} } */
>>> > +/* { dg-final { scan-rtl-dump "pclmulqdq" "dfinish"} } */
>>> > diff --git a/gcc/testsuite/gcc.target/i386/crc-CCIT-data16-pclmul.c
>>> b/gcc/testsuite/gcc.target/i386/crc-CCIT-data16-pclmul.c
>>> > new file mode 100644
>>> > index 00000000000..1676eb5265b
>>> > --- /dev/null
>>> > +++ b/gcc/testsuite/gcc.target/i386/crc-CCIT-data16-pclmul.c
>>> > @@ -0,0 +1,9 @@
>>> > +/* { dg-do run } */
>>> > +/* { dg-options "-w -mpclmul -O2 -fdump-rtl-dfinish -fdump-tree-crc" }
>>> */
>>> > +/* { dg-skip-if "" { *-*-* } { "-flto"} } */
>>> > +
>>> > +#include "../../gcc.dg/torture/crc-CCIT-data16.c"
>>> > +
>>> > +/* { dg-final { scan-tree-dump "calculates CRC!" "crc"} } */
>>> > +/* { dg-final { scan-tree-dump-times "Couldn't generate faster CRC
>>> code." 0 "crc"} } */
>>> > +/* { dg-final { scan-rtl-dump "pclmulqdq" "dfinish"} } */
>>> > diff --git a/gcc/testsuite/gcc.target/i386/crc-CCIT-data8-pclmul.c
>>> b/gcc/testsuite/gcc.target/i386/crc-CCIT-data8-pclmul.c
>>> > new file mode 100644
>>> > index 00000000000..241181f89e2
>>> > --- /dev/null
>>> > +++ b/gcc/testsuite/gcc.target/i386/crc-CCIT-data8-pclmul.c
>>> > @@ -0,0 +1,9 @@
>>> > +/* { dg-do run } */
>>> > +/* { dg-options "-w -mpclmul -O2 -fdump-rtl-dfinish -fdump-tree-crc" }
>>> */
>>> > +/* { dg-skip-if "" { *-*-* } { "-flto" } } */
>>> > +
>>> > +#include "../../gcc.dg/torture/crc-CCIT-data8.c"
>>> > +
>>> > +/* { dg-final { scan-tree-dump "calculates CRC!" "crc"} } */
>>> > +/* { dg-final { scan-tree-dump-times "Couldn't generate faster CRC
>>> code." 0 "crc"} } */
>>> > +/* { dg-final { scan-rtl-dump "pclmulqdq" "dfinish"} } */
>>> > diff --git
>>> a/gcc/testsuite/gcc.target/i386/crc-coremark-16bitdata-pclmul.c
>>> b/gcc/testsuite/gcc.target/i386/crc-coremark-16bitdata-pclmul.c
>>> > new file mode 100644
>>> > index 00000000000..c64d17e30fd
>>> > --- /dev/null
>>> > +++ b/gcc/testsuite/gcc.target/i386/crc-coremark-16bitdata-pclmul.c
>>> > @@ -0,0 +1,9 @@
>>> > +/* { dg-do run } */
>>> > +/* { dg-options "-w -mpclmul -O2 -fdump-rtl-dfinish -fdump-tree-crc" }
>>> */
>>> > +/* { dg-skip-if "" { *-*-* } { "-flto"} } */
>>> > +
>>> > +#include "../../gcc.dg/torture/crc-coremark16-data16.c"
>>> > +
>>> > +/* { dg-final { scan-tree-dump "calculates CRC!" "crc"} } */
>>> > +/* { dg-final { scan-tree-dump-times "Couldn't generate faster CRC
>>> code." 0 "crc"} } */
>>> > +/* { dg-final { scan-rtl-dump "pclmulqdq" "dfinish"} } */
>>> > diff --git a/gcc/testsuite/gcc.target/i386/crc-crc32-data16.c
>>> b/gcc/testsuite/gcc.target/i386/crc-crc32-data16.c
>>> > new file mode 100644
>>> > index 00000000000..49ab5f31ef0
>>> > --- /dev/null
>>> > +++ b/gcc/testsuite/gcc.target/i386/crc-crc32-data16.c
>>> > @@ -0,0 +1,53 @@
>>> > +/* { dg-do run } */
>>> > +/* { dg-options "-mcrc32 -O2 -fdump-rtl-dfinish -fdump-tree-crc" } */
>>> > +/* { dg-skip-if "" { *-*-* } { "-flto"} } */
>>> > +
>>> > +#include <stdint.h>
>>> > +#include <stdlib.h>
>>> > +
>>> > +__attribute__ ((noinline,optimize(0)))
>>> > +uint32_t _crc32_O0 (uint32_t crc, uint16_t data) {
>>> > + int i;
>>> > + crc = crc ^ data;
>>> > +
>>> > + for (i = 0; i < 8; i++) {
>>> > + if (crc & 1)
>>> > + crc = (crc >> 1) ^ 0x82F63B78;
>>> > + else
>>> > + crc = (crc >> 1);
>>> > + }
>>> > +
>>> > + return crc;
>>> > +}
>>> > +
>>> > +uint32_t _crc32 (uint32_t crc, uint16_t data) {
>>> > + int i;
>>> > + crc = crc ^ data;
>>> > +
>>> > + for (i = 0; i < 8; i++) {
>>> > + if (crc & 1)
>>> > + crc = (crc >> 1) ^ 0x82F63B78;
>>> > + else
>>> > + crc = (crc >> 1);
>>> > + }
>>> > +
>>> > + return crc;
>>> > +}
>>> > +
>>> > +int main ()
>>> > +{
>>> > + uint32_t crc = 0x0D800D80;
>>> > + for (uint16_t i = 0; i < 0xffff; i++)
>>> > + {
>>> > + uint32_t res1 = _crc32_O0 (crc, i);
>>> > + uint32_t res2 = _crc32 (crc, i);
>>> > + if (res1 != res2)
>>> > + abort ();
>>> > + crc = res1;
>>> > + }
>>> > +}
>>> > +
>>> > +/* { dg-final { scan-tree-dump "calculates CRC!" "crc"} } */
>>> > +/* { dg-final { scan-tree-dump-times "Couldn't generate faster CRC
>>> code." 0 "crc"} } */
>>> > +/* { dg-final { scan-rtl-dump "UNSPEC_CRC32" "dfinish"} } */
>>> > +/* { dg-final { scan-rtl-dump-times "pclmulqdq" 0 "dfinish"} } */
>>> > diff --git a/gcc/testsuite/gcc.target/i386/crc-crc32-data32.c
>>> b/gcc/testsuite/gcc.target/i386/crc-crc32-data32.c
>>> > new file mode 100644
>>> > index 00000000000..08d6c193a77
>>> > --- /dev/null
>>> > +++ b/gcc/testsuite/gcc.target/i386/crc-crc32-data32.c
>>> > @@ -0,0 +1,53 @@
>>> > +/* { dg-do run } */
>>> > +/* { dg-options "-mcrc32 -O2 -fdump-rtl-dfinish -fdump-tree-crc" } */
>>> > +/* { dg-skip-if "" { *-*-* } { "-flto"} } */
>>> > +
>>> > +#include <stdint.h>
>>> > +#include <stdlib.h>
>>> > +
>>> > +__attribute__ ((noinline,optimize(0)))
>>> > +uint32_t _crc32_O0 (uint32_t crc, uint32_t data) {
>>> > + int i;
>>> > + crc = crc ^ data;
>>> > +
>>> > + for (i = 0; i < 32; i++) {
>>> > + if (crc & 1)
>>> > + crc = (crc >> 1) ^ 0x82F63B78;
>>> > + else
>>> > + crc = (crc >> 1);
>>> > + }
>>> > +
>>> > + return crc;
>>> > +}
>>> > +
>>> > +uint32_t _crc32 (uint32_t crc, uint32_t data) {
>>> > + int i;
>>> > + crc = crc ^ data;
>>> > +
>>> > + for (i = 0; i < 32; i++) {
>>> > + if (crc & 1)
>>> > + crc = (crc >> 1) ^ 0x82F63B78;
>>> > + else
>>> > + crc = (crc >> 1);
>>> > + }
>>> > +
>>> > + return crc;
>>> > +}
>>> > +
>>> > +int main ()
>>> > +{
>>> > + uint32_t crc = 0x0D800D80;
>>> > + for (uint8_t i = 0; i < 0xff; i++)
>>> > + {
>>> > + uint32_t res1 = _crc32_O0 (crc, i);
>>> > + uint32_t res2 = _crc32 (crc, i);
>>> > + if (res1 != res2)
>>> > + abort ();
>>> > + crc = res1;
>>> > + }
>>> > +}
>>> > +
>>> > +/* { dg-final { scan-tree-dump "calculates CRC!" "crc"} } */
>>> > +/* { dg-final { scan-tree-dump-times "Couldn't generate faster CRC
>>> code." 0 "crc"} } */
>>> > +/* { dg-final { scan-rtl-dump "UNSPEC_CRC32" "dfinish"} } */
>>> > +/* { dg-final { scan-rtl-dump-times "pclmulqdq" 0 "dfinish"} } */
>>> > diff --git a/gcc/testsuite/gcc.target/i386/crc-crc32-data8.c
>>> b/gcc/testsuite/gcc.target/i386/crc-crc32-data8.c
>>> > new file mode 100644
>>> > index 00000000000..7a76b27fd28
>>> > --- /dev/null
>>> > +++ b/gcc/testsuite/gcc.target/i386/crc-crc32-data8.c
>>> > @@ -0,0 +1,53 @@
>>> > +/* { dg-do run } */
>>> > +/* { dg-options "-mcrc32 -O2 -fdump-rtl-dfinish -fdump-tree-crc" } */
>>> > +/* { dg-skip-if "" { *-*-* } { "-flto"} } */
>>> > +
>>> > +#include <stdint.h>
>>> > +#include <stdlib.h>
>>> > +
>>> > +__attribute__ ((noinline,optimize(0)))
>>> > +uint32_t _crc32_O0 (uint32_t crc, uint8_t data) {
>>> > + int i;
>>> > + crc = crc ^ data;
>>> > +
>>> > + for (i = 0; i < 8; i++) {
>>> > + if (crc & 1)
>>> > + crc = (crc >> 1) ^ 0x82F63B78;
>>> > + else
>>> > + crc = (crc >> 1);
>>> > + }
>>> > +
>>> > + return crc;
>>> > +}
>>> > +
>>> > +uint32_t _crc32 (uint32_t crc, uint8_t data) {
>>> > + int i;
>>> > + crc = crc ^ data;
>>> > +
>>> > + for (i = 0; i < 8; i++) {
>>> > + if (crc & 1)
>>> > + crc = (crc >> 1) ^ 0x82F63B78;
>>> > + else
>>> > + crc = (crc >> 1);
>>> > + }
>>> > +
>>> > + return crc;
>>> > +}
>>> > +
>>> > +int main ()
>>> > +{
>>> > + uint32_t crc = 0x0D800D80;
>>> > + for (uint8_t i = 0; i < 0xff; i++)
>>> > + {
>>> > + uint32_t res1 = _crc32_O0 (crc, i);
>>> > + uint32_t res2 = _crc32 (crc, i);
>>> > + if (res1 != res2)
>>> > + abort ();
>>> > + crc = res1;
>>> > + }
>>> > +}
>>> > +
>>> > +/* { dg-final { scan-tree-dump "calculates CRC!" "crc"} } */
>>> > +/* { dg-final { scan-tree-dump-times "Couldn't generate faster CRC
>>> code." 0 "crc"} } */
>>> > +/* { dg-final { scan-rtl-dump "UNSPEC_CRC32" "dfinish"} } */
>>> > +/* { dg-final { scan-rtl-dump-times "pclmulqdq" 0 "dfinish"} } */
>>> > --
>>> > 2.55.0
>>>
>>>
