Richard Biener <[email protected]> writes:
> This is another place where we fail to pass down the mode of a
> CONST_INT.
>
> Bootstrapped and tested on x86_64-unknown-linux-gnu, OK?
>
> Thanks,
> Richard.
>
> 2022-05-24 Richard Biener <[email protected]>
>
> PR middle-end/105711
> * expmed.cc (extract_bit_field_as_subreg): Add op0_mode parameter
> and use it.
> (extract_bit_field_1): Pass down the mode of op0 to
> extract_bit_field_as_subreg.
>
> * gcc.target/i386/pr105711.c: New testcase.
LGTM, but I guess the new parameter should be documented above
extract_bit_field_as_subreg.
Thanks,
Richard
> ---
> gcc/expmed.cc | 15 +++++++++------
> gcc/testsuite/gcc.target/i386/pr105711.c | 12 ++++++++++++
> 2 files changed, 21 insertions(+), 6 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/i386/pr105711.c
>
> diff --git a/gcc/expmed.cc b/gcc/expmed.cc
> index 41738c1efe9..e22278370fd 100644
> --- a/gcc/expmed.cc
> +++ b/gcc/expmed.cc
> @@ -1611,14 +1611,15 @@ extract_bit_field_using_extv (const extraction_insn
> *extv, rtx op0,
>
> static rtx
> extract_bit_field_as_subreg (machine_mode mode, rtx op0,
> + machine_mode op0_mode,
> poly_uint64 bitsize, poly_uint64 bitnum)
> {
> poly_uint64 bytenum;
> if (multiple_p (bitnum, BITS_PER_UNIT, &bytenum)
> && known_eq (bitsize, GET_MODE_BITSIZE (mode))
> - && lowpart_bit_field_p (bitnum, bitsize, GET_MODE (op0))
> - && TRULY_NOOP_TRUNCATION_MODES_P (mode, GET_MODE (op0)))
> - return simplify_gen_subreg (mode, op0, GET_MODE (op0), bytenum);
> + && lowpart_bit_field_p (bitnum, bitsize, op0_mode)
> + && TRULY_NOOP_TRUNCATION_MODES_P (mode, op0_mode))
> + return simplify_gen_subreg (mode, op0, op0_mode, bytenum);
> return NULL_RTX;
> }
>
> @@ -1777,7 +1778,8 @@ extract_bit_field_1 (rtx str_rtx, poly_uint64 bitsize,
> poly_uint64 bitnum,
> for valid bitsize and bitnum, so we don't need to do that here. */
> if (VECTOR_MODE_P (mode))
> {
> - rtx sub = extract_bit_field_as_subreg (mode, op0, bitsize, bitnum);
> + rtx sub = extract_bit_field_as_subreg (mode, op0, outermode,
> + bitsize, bitnum);
> if (sub)
> return sub;
> }
> @@ -1824,9 +1826,10 @@ extract_bit_field_1 (rtx str_rtx, poly_uint64 bitsize,
> poly_uint64 bitnum,
> /* Extraction of a full MODE1 value can be done with a subreg as long
> as the least significant bit of the value is the least significant
> bit of either OP0 or a word of OP0. */
> - if (!MEM_P (op0) && !reverse)
> + if (!MEM_P (op0) && !reverse && op0_mode.exists (&imode))
> {
> - rtx sub = extract_bit_field_as_subreg (mode1, op0, bitsize, bitnum);
> + rtx sub = extract_bit_field_as_subreg (mode1, op0, imode,
> + bitsize, bitnum);
> if (sub)
> return convert_extracted_bit_field (sub, mode, tmode, unsignedp);
> }
> diff --git a/gcc/testsuite/gcc.target/i386/pr105711.c
> b/gcc/testsuite/gcc.target/i386/pr105711.c
> new file mode 100644
> index 00000000000..6d07e08138a
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr105711.c
> @@ -0,0 +1,12 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 --param=sccvn-max-alias-queries-per-access=0" } */
> +
> +int *p, a, b;
> +
> +void
> +foo (_Complex char c)
> +{
> + c /= 3040;
> + a %= __builtin_memcmp (1 + &c, p, 1);
> + b = c + __imag__ c;
> +}
