https://gcc.gnu.org/g:aa29654b1128a572c97fcaba94095f493662a0db
commit r16-276-gaa29654b1128a572c97fcaba94095f493662a0db
Author: Uros Bizjak <ubiz...@gmail.com>
Date: Tue Apr 29 10:25:45 2025 +0200
i386: Allow string instructions from non-default address space [PR111657]
MOVS instructions allow segment override of their source operand, e.g.:
rep movsq %gs:(%rsi), (%rdi)
where %rsi is the address of the source location (with %gs segment override)
and %rdi is the address of the destination location.
The testcase improves from (-O2 -mno-sse -mtune=generic):
xorl %eax, %eax
.L2:
movl %eax, %edx
addl $8, %eax
movq %gs:m(%rdx), %rcx
movq %rcx, (%rdi,%rdx)
cmpl $240, %eax
jb .L2
ret
to:
movl $m, %esi
movl $30, %ecx
rep movsq %gs:(%rsi), (%rdi)
ret
PR target/111657
gcc/ChangeLog:
* config/i386/i386-expand.cc (alg_usable_p): Remove have_as bool
argument and add dst_as and src_as address space arguments. Reject
libcall algorithm with dst_as and src_as in the non-default address
spaces. Reject rep_prefix_{1,4,8}_byte algorithms with dst_as in
the non-default address space.
(decide_alg): Remove have_as bool argument and add dst_as and src_as
address space arguments. Update calls to alg_usable_p.
(ix86_expand_set_or_cpymem): Update call to decide_alg.
* config/i386/i386.md (strmov): Do not fail if operand[3] (source)
is in the non-default address space. Expand with
gen_strmov_singleop
only when operand[1] (destination) is in the default address space.
(*strmovdi_rex_1): Determine memory operands from insn pattern.
Allow only when destination is in the default address space.
Rewrite asm template to use explicit operands.
(*strmovsi_1): Ditto.
(*strmovhi_1): DItto.
(*strmovqi_1): Ditto.
(*rep_movdi_rex64): Ditto.
(*rep_movsi): Ditto.
(*rep_movqi): Ditto.
(*strsetdi_rex_1): Determine memory operands from insn pattern.
Allow only when destination is in the default address space.
(*strsetsi_1): Ditto.
(*strsethi_1): Ditto.
(*strsetqi_1): Ditto.
(*rep_stosdi_rex64): Ditto.
(*rep_stossi): Ditto.
(*rep_stosqi): Ditto.
gcc/testsuite/ChangeLog:
* gcc.target/i386/pr111657-1.c: New test.
Diff:
---
gcc/config/i386/i386-expand.cc | 56 +++++++-------
gcc/config/i386/i386.md | 116 ++++++++++++++++++++++-------
gcc/testsuite/gcc.target/i386/pr111657-1.c | 11 +++
3 files changed, 131 insertions(+), 52 deletions(-)
diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
index 388e65192e48..f1cc85b4531c 100644
--- a/gcc/config/i386/i386-expand.cc
+++ b/gcc/config/i386/i386-expand.cc
@@ -8907,31 +8907,33 @@ expand_set_or_cpymem_constant_prologue (rtx dst, rtx
*srcp, rtx destreg,
/* Return true if ALG can be used in current context.
Assume we expand memset if MEMSET is true. */
static bool
-alg_usable_p (enum stringop_alg alg, bool memset, bool have_as)
+alg_usable_p (enum stringop_alg alg, bool memset,
+ addr_space_t dst_as, addr_space_t src_as)
{
if (alg == no_stringop)
return false;
/* It is not possible to use a library call if we have non-default
address space. We can do better than the generic byte-at-a-time
loop, used as a fallback. */
- if (alg == libcall && have_as)
+ if (alg == libcall &&
+ !(ADDR_SPACE_GENERIC_P (dst_as) && ADDR_SPACE_GENERIC_P (src_as)))
return false;
if (alg == vector_loop)
return TARGET_SSE || TARGET_AVX;
/* Algorithms using the rep prefix want at least edi and ecx;
additionally, memset wants eax and memcpy wants esi. Don't
consider such algorithms if the user has appropriated those
- registers for their own purposes, or if we have a non-default
- address space, since some string insns cannot override the segment. */
+ registers for their own purposes, or if we have the destination
+ in the non-default address space, since string insns cannot
+ override the destination segment. */
if (alg == rep_prefix_1_byte
|| alg == rep_prefix_4_byte
|| alg == rep_prefix_8_byte)
{
- if (have_as)
- return false;
if (fixed_regs[CX_REG]
|| fixed_regs[DI_REG]
- || (memset ? fixed_regs[AX_REG] : fixed_regs[SI_REG]))
+ || (memset ? fixed_regs[AX_REG] : fixed_regs[SI_REG])
+ || !ADDR_SPACE_GENERIC_P (dst_as))
return false;
}
return true;
@@ -8941,8 +8943,8 @@ alg_usable_p (enum stringop_alg alg, bool memset, bool
have_as)
static enum stringop_alg
decide_alg (HOST_WIDE_INT count, HOST_WIDE_INT expected_size,
unsigned HOST_WIDE_INT min_size, unsigned HOST_WIDE_INT max_size,
- bool memset, bool zero_memset, bool have_as,
- int *dynamic_check, bool *noalign, bool recur)
+ bool memset, bool zero_memset, addr_space_t dst_as,
+ addr_space_t src_as, int *dynamic_check, bool *noalign, bool recur)
{
const struct stringop_algs *algs;
bool optimize_for_speed;
@@ -8974,7 +8976,7 @@ decide_alg (HOST_WIDE_INT count, HOST_WIDE_INT
expected_size,
for (i = 0; i < MAX_STRINGOP_ALGS; i++)
{
enum stringop_alg candidate = algs->size[i].alg;
- bool usable = alg_usable_p (candidate, memset, have_as);
+ bool usable = alg_usable_p (candidate, memset, dst_as, src_as);
any_alg_usable_p |= usable;
if (candidate != libcall && candidate && usable)
@@ -8990,17 +8992,17 @@ decide_alg (HOST_WIDE_INT count, HOST_WIDE_INT
expected_size,
/* If user specified the algorithm, honor it if possible. */
if (ix86_stringop_alg != no_stringop
- && alg_usable_p (ix86_stringop_alg, memset, have_as))
+ && alg_usable_p (ix86_stringop_alg, memset, dst_as, src_as))
return ix86_stringop_alg;
/* rep; movq or rep; movl is the smallest variant. */
else if (!optimize_for_speed)
{
*noalign = true;
if (!count || (count & 3) || (memset && !zero_memset))
- return alg_usable_p (rep_prefix_1_byte, memset, have_as)
+ return alg_usable_p (rep_prefix_1_byte, memset, dst_as, src_as)
? rep_prefix_1_byte : loop_1_byte;
else
- return alg_usable_p (rep_prefix_4_byte, memset, have_as)
+ return alg_usable_p (rep_prefix_4_byte, memset, dst_as, src_as)
? rep_prefix_4_byte : loop;
}
/* Very tiny blocks are best handled via the loop, REP is expensive to
@@ -9024,7 +9026,7 @@ decide_alg (HOST_WIDE_INT count, HOST_WIDE_INT
expected_size,
enum stringop_alg candidate = algs->size[i].alg;
if (candidate != libcall
- && alg_usable_p (candidate, memset, have_as))
+ && alg_usable_p (candidate, memset, dst_as, src_as))
{
alg = candidate;
alg_noalign = algs->size[i].noalign;
@@ -9044,7 +9046,7 @@ decide_alg (HOST_WIDE_INT count, HOST_WIDE_INT
expected_size,
else if (!any_alg_usable_p)
break;
}
- else if (alg_usable_p (candidate, memset, have_as)
+ else if (alg_usable_p (candidate, memset, dst_as, src_as)
&& !(TARGET_PREFER_KNOWN_REP_MOVSB_STOSB
&& candidate == rep_prefix_1_byte
/* NB: If min_size != max_size, size is
@@ -9066,7 +9068,7 @@ decide_alg (HOST_WIDE_INT count, HOST_WIDE_INT
expected_size,
choice in ix86_costs. */
if ((TARGET_INLINE_ALL_STRINGOPS || TARGET_INLINE_STRINGOPS_DYNAMICALLY)
&& (algs->unknown_size == libcall
- || !alg_usable_p (algs->unknown_size, memset, have_as)))
+ || !alg_usable_p (algs->unknown_size, memset, dst_as, src_as)))
{
enum stringop_alg alg;
HOST_WIDE_INT new_expected_size = (max > 0 ? max : 4096) / 2;
@@ -9081,8 +9083,9 @@ decide_alg (HOST_WIDE_INT count, HOST_WIDE_INT
expected_size,
*dynamic_check = 128;
return loop_1_byte;
}
- alg = decide_alg (count, new_expected_size, min_size, max_size, memset,
- zero_memset, have_as, dynamic_check, noalign, true);
+ alg = decide_alg (count, new_expected_size, min_size, max_size,
+ memset, zero_memset, dst_as, src_as,
+ dynamic_check, noalign, true);
gcc_assert (*dynamic_check == -1);
if (TARGET_INLINE_STRINGOPS_DYNAMICALLY)
*dynamic_check = max;
@@ -9094,7 +9097,11 @@ decide_alg (HOST_WIDE_INT count, HOST_WIDE_INT
expected_size,
/* Try to use some reasonable fallback algorithm. Note that for
non-default address spaces we default to a loop instead of
a libcall. */
- return (alg_usable_p (algs->unknown_size, memset, have_as)
+
+ bool have_as = !(ADDR_SPACE_GENERIC_P (dst_as)
+ && ADDR_SPACE_GENERIC_P (src_as));
+
+ return (alg_usable_p (algs->unknown_size, memset, dst_as, src_as)
? algs->unknown_size : have_as ? loop : libcall);
}
@@ -9320,7 +9327,7 @@ ix86_expand_set_or_cpymem (rtx dst, rtx src, rtx
count_exp, rtx val_exp,
unsigned HOST_WIDE_INT max_size = -1;
unsigned HOST_WIDE_INT probable_max_size = -1;
bool misaligned_prologue_used = false;
- bool have_as;
+ addr_space_t dst_as, src_as = ADDR_SPACE_GENERIC;
if (CONST_INT_P (align_exp))
align = INTVAL (align_exp);
@@ -9358,16 +9365,15 @@ ix86_expand_set_or_cpymem (rtx dst, rtx src, rtx
count_exp, rtx val_exp,
if (count > (HOST_WIDE_INT_1U << 30))
return false;
- have_as = !ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (dst));
+ dst_as = MEM_ADDR_SPACE (dst);
if (!issetmem)
- have_as |= !ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (src));
+ src_as = MEM_ADDR_SPACE (src);
/* Step 0: Decide on preferred algorithm, desired alignment and
size of chunks to be copied by main loop. */
alg = decide_alg (count, expected_size, min_size, probable_max_size,
- issetmem,
- issetmem && val_exp == const0_rtx, have_as,
- &dynamic_check, &noalign, false);
+ issetmem, issetmem && val_exp == const0_rtx,
+ dst_as, src_as, &dynamic_check, &noalign, false);
if (dump_file)
fprintf (dump_file, "Selected stringop expansion strategy: %s\n",
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index e170da3b0e64..962e7ab92aa8 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -25587,10 +25587,6 @@
(clobber (reg:CC FLAGS_REG))])]
""
{
- /* Can't use this for non-default address spaces. */
- if (!ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (operands[3])))
- FAIL;
-
int piece_size = GET_MODE_SIZE (GET_MODE (operands[1]));
/* If .md ever supports :P for Pmode, these can be directly
@@ -25598,9 +25594,12 @@
operands[5] = plus_constant (Pmode, operands[0], piece_size);
operands[6] = plus_constant (Pmode, operands[2], piece_size);
- /* Can't use this if the user has appropriated esi or edi. */
+ /* Can't use this if the user has appropriated esi or edi,
+ * or if we have the destination in the non-default address space,
+ * since string insns cannot override the destination segment. */
if ((TARGET_SINGLE_STRINGOP || optimize_insn_for_size_p ())
- && !(fixed_regs[SI_REG] || fixed_regs[DI_REG]))
+ && !(fixed_regs[SI_REG] || fixed_regs[DI_REG])
+ && ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (operands[1])))
{
emit_insn (gen_strmov_singleop (operands[0], operands[1],
operands[2], operands[3],
@@ -25635,8 +25634,16 @@
(const_int 8)))]
"TARGET_64BIT
&& !(fixed_regs[SI_REG] || fixed_regs[DI_REG])
- && ix86_check_no_addr_space (insn)"
- "%^movsq"
+ && ADDR_SPACE_GENERIC_P
+ (MEM_ADDR_SPACE (SET_DEST (XVECEXP (PATTERN (insn), 0, 0))))"
+{
+ rtx exp = XVECEXP (PATTERN (insn), 0, 0);
+
+ operands[0] = SET_DEST (exp);
+ operands[1] = SET_SRC (exp);
+
+ return "%^movsq\t{%1, %0|%0, %1}";
+}
[(set_attr "type" "str")
(set_attr "memory" "both")
(set_attr "mode" "DI")])
@@ -25651,8 +25658,16 @@
(plus:P (match_dup 3)
(const_int 4)))]
"!(fixed_regs[SI_REG] || fixed_regs[DI_REG])
- && ix86_check_no_addr_space (insn)"
- "%^movs{l|d}"
+ && ADDR_SPACE_GENERIC_P
+ (MEM_ADDR_SPACE (SET_DEST (XVECEXP (PATTERN (insn), 0, 0))))"
+{
+ rtx exp = XVECEXP (PATTERN (insn), 0, 0);
+
+ operands[0] = SET_DEST (exp);
+ operands[1] = SET_SRC (exp);
+
+ return "%^movs{l|d}\t{%1, %0|%0, %1}";
+}
[(set_attr "type" "str")
(set_attr "memory" "both")
(set_attr "mode" "SI")])
@@ -25667,8 +25682,16 @@
(plus:P (match_dup 3)
(const_int 2)))]
"!(fixed_regs[SI_REG] || fixed_regs[DI_REG])
- && ix86_check_no_addr_space (insn)"
- "%^movsw"
+ && ADDR_SPACE_GENERIC_P
+ (MEM_ADDR_SPACE (SET_DEST (XVECEXP (PATTERN (insn), 0, 0))))"
+{
+ rtx exp = XVECEXP (PATTERN (insn), 0, 0);
+
+ operands[0] = SET_DEST (exp);
+ operands[1] = SET_SRC (exp);
+
+ return "%^movsw\t{%1, %0|%0, %1}";
+}
[(set_attr "type" "str")
(set_attr "memory" "both")
(set_attr "mode" "HI")])
@@ -25683,8 +25706,16 @@
(plus:P (match_dup 3)
(const_int 1)))]
"!(fixed_regs[SI_REG] || fixed_regs[DI_REG])
- && ix86_check_no_addr_space (insn)"
- "%^movsb"
+ && ADDR_SPACE_GENERIC_P
+ (MEM_ADDR_SPACE (SET_DEST (XVECEXP (PATTERN (insn), 0, 0))))"
+{
+ rtx exp = XVECEXP (PATTERN (insn), 0, 0);
+
+ operands[0] = SET_DEST (exp);
+ operands[1] = SET_SRC (exp);
+
+ return "%^movsb\t{%1, %0|%0, %1}";
+}
[(set_attr "type" "str")
(set_attr "memory" "both")
(set (attr "prefix_rex")
@@ -25723,8 +25754,16 @@
(use (match_dup 5))]
"TARGET_64BIT
&& !(fixed_regs[CX_REG] || fixed_regs[SI_REG] || fixed_regs[DI_REG])
- && ix86_check_no_addr_space (insn)"
- "%^rep{%;} movsq"
+ && ADDR_SPACE_GENERIC_P
+ (MEM_ADDR_SPACE (SET_DEST (XVECEXP (PATTERN (insn), 0, 3))))"
+{
+ rtx exp = XVECEXP (PATTERN (insn), 0, 3);
+
+ operands[0] = SET_DEST (exp);
+ operands[1] = SET_SRC (exp);
+
+ return "%^rep{%;} movsq\t{%1, %0|%0, %1}";
+}
[(set_attr "type" "str")
(set_attr "prefix_rep" "1")
(set_attr "memory" "both")
@@ -25743,8 +25782,16 @@
(mem:BLK (match_dup 4)))
(use (match_dup 5))]
"!(fixed_regs[CX_REG] || fixed_regs[SI_REG] || fixed_regs[DI_REG])
- && ix86_check_no_addr_space (insn)"
- "%^rep{%;} movs{l|d}"
+ && ADDR_SPACE_GENERIC_P
+ (MEM_ADDR_SPACE (SET_DEST (XVECEXP (PATTERN (insn), 0, 3))))"
+{
+ rtx exp = XVECEXP (PATTERN (insn), 0, 3);
+
+ operands[0] = SET_DEST (exp);
+ operands[1] = SET_SRC (exp);
+
+ return "%^rep{%;} movs{l|d}\t{%1, %0|%0, %1}";
+}
[(set_attr "type" "str")
(set_attr "prefix_rep" "1")
(set_attr "memory" "both")
@@ -25761,8 +25808,16 @@
(mem:BLK (match_dup 4)))
(use (match_dup 5))]
"!(fixed_regs[CX_REG] || fixed_regs[SI_REG] || fixed_regs[DI_REG])
- && ix86_check_no_addr_space (insn)"
- "%^rep{%;} movsb"
+ && ADDR_SPACE_GENERIC_P
+ (MEM_ADDR_SPACE (SET_DEST (XVECEXP (PATTERN (insn), 0, 3))))"
+{
+ rtx exp = XVECEXP (PATTERN (insn), 0, 3);
+
+ operands[0] = SET_DEST (exp);
+ operands[1] = SET_SRC (exp);
+
+ return "%^rep{%;} movsb\t{%1, %0|%0, %1}";
+}
[(set_attr "type" "str")
(set_attr "prefix_rep" "1")
(set_attr "memory" "both")
@@ -25844,7 +25899,8 @@
(unspec [(const_int 0)] UNSPEC_STOS)]
"TARGET_64BIT
&& !(fixed_regs[AX_REG] || fixed_regs[DI_REG])
- && ix86_check_no_addr_space (insn)"
+ && ADDR_SPACE_GENERIC_P
+ (MEM_ADDR_SPACE (SET_DEST (XVECEXP (PATTERN (insn), 0, 0))))"
"%^stosq"
[(set_attr "type" "str")
(set_attr "memory" "store")
@@ -25858,7 +25914,8 @@
(const_int 4)))
(unspec [(const_int 0)] UNSPEC_STOS)]
"!(fixed_regs[AX_REG] || fixed_regs[DI_REG])
- && ix86_check_no_addr_space (insn)"
+ && ADDR_SPACE_GENERIC_P
+ (MEM_ADDR_SPACE (SET_DEST (XVECEXP (PATTERN (insn), 0, 0))))"
"%^stos{l|d}"
[(set_attr "type" "str")
(set_attr "memory" "store")
@@ -25872,7 +25929,8 @@
(const_int 2)))
(unspec [(const_int 0)] UNSPEC_STOS)]
"!(fixed_regs[AX_REG] || fixed_regs[DI_REG])
- && ix86_check_no_addr_space (insn)"
+ && ADDR_SPACE_GENERIC_P
+ (MEM_ADDR_SPACE (SET_DEST (XVECEXP (PATTERN (insn), 0, 0))))"
"%^stosw"
[(set_attr "type" "str")
(set_attr "memory" "store")
@@ -25886,7 +25944,8 @@
(const_int 1)))
(unspec [(const_int 0)] UNSPEC_STOS)]
"!(fixed_regs[AX_REG] || fixed_regs[DI_REG])
- && ix86_check_no_addr_space (insn)"
+ && ADDR_SPACE_GENERIC_P
+ (MEM_ADDR_SPACE (SET_DEST (XVECEXP (PATTERN (insn), 0, 0))))"
"%^stosb"
[(set_attr "type" "str")
(set_attr "memory" "store")
@@ -25922,7 +25981,8 @@
(use (match_dup 4))]
"TARGET_64BIT
&& !(fixed_regs[AX_REG] || fixed_regs[CX_REG] || fixed_regs[DI_REG])
- && ix86_check_no_addr_space (insn)"
+ && ADDR_SPACE_GENERIC_P
+ (MEM_ADDR_SPACE (SET_DEST (XVECEXP (PATTERN (insn), 0, 2))))"
"%^rep{%;} stosq"
[(set_attr "type" "str")
(set_attr "prefix_rep" "1")
@@ -25940,7 +26000,8 @@
(use (match_operand:SI 2 "register_operand" "a"))
(use (match_dup 4))]
"!(fixed_regs[AX_REG] || fixed_regs[CX_REG] || fixed_regs[DI_REG])
- && ix86_check_no_addr_space (insn)"
+ && ADDR_SPACE_GENERIC_P
+ (MEM_ADDR_SPACE (SET_DEST (XVECEXP (PATTERN (insn), 0, 2))))"
"%^rep{%;} stos{l|d}"
[(set_attr "type" "str")
(set_attr "prefix_rep" "1")
@@ -25957,7 +26018,8 @@
(use (match_operand:QI 2 "register_operand" "a"))
(use (match_dup 4))]
"!(fixed_regs[AX_REG] || fixed_regs[CX_REG] || fixed_regs[DI_REG])
- && ix86_check_no_addr_space (insn)"
+ && ADDR_SPACE_GENERIC_P
+ (MEM_ADDR_SPACE (SET_DEST (XVECEXP (PATTERN (insn), 0, 2))))"
"%^rep{%;} stosb"
[(set_attr "type" "str")
(set_attr "prefix_rep" "1")
diff --git a/gcc/testsuite/gcc.target/i386/pr111657-1.c
b/gcc/testsuite/gcc.target/i386/pr111657-1.c
new file mode 100644
index 000000000000..69117b72cdf1
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr111657-1.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mno-sse -mtune=generic -masm=att" } */
+
+typedef unsigned long uword __attribute__ ((mode (word)));
+
+struct a { uword arr[30]; };
+
+__seg_gs struct a m;
+void bar (struct a *dst) { *dst = m; }
+
+/* { dg-final { scan-assembler "rep\[; \t\]+movs(l|q)\[ \t\]+%gs:" } } */
