LGTM

Liao Shihua <shihua@iscas.ac.cn> 於 2024年5月24日 週五 13:05 寫道：

> Update v1->v2
>     Add testcase for this patch.
>
> Missing boolean_expression TARGET_ZMMUL in riscv_rtx_costs() cause
> different instructions when
> multiplying an integer with a constant. (
> https://github.com/riscv-collab/riscv-gnu-toolchain/issues/1482 )
>
> int foo(int *ib) {
>     *ib = *ib * 33938;
>     return 0;
> }
>
> rv64im:
>         lw      a4,0(a1)
>         li      a5,32768
>         addiw   a5,a5,1170
>         mulw    a5,a5,a4
>         sw      a5,0(a1)
>         ret
>
> rv64i_zmmul:
>         lw      a4,0(a1)
>         slliw   a5,a4,5
>         addw    a5,a5,a4
>         slliw   a5,a5,3
>         addw    a5,a5,a4
>         slliw   a5,a5,3
>         addw    a5,a5,a4
>         slliw   a5,a5,3
>         addw    a5,a5,a4
>         slliw   a5,a5,1
>         sw      a5,0(a1)
>         ret
>
> Fixed.
>
> gcc/ChangeLog:
>
>         * config/riscv/riscv.cc (riscv_rtx_costs): Add TARGET_ZMMUL.
>
> gcc/testsuite/ChangeLog:
>
>         * gcc.target/riscv/zmmul-3.c: New test.
>
> ---
>  gcc/config/riscv/riscv.cc                | 2 +-
>  gcc/testsuite/gcc.target/riscv/zmmul-3.c | 8 ++++++++
>  2 files changed, 9 insertions(+), 1 deletion(-)
>  create mode 100644 gcc/testsuite/gcc.target/riscv/zmmul-3.c
>
> diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
> index 85df5b7ab49..580ae007181 100644
> --- a/gcc/config/riscv/riscv.cc
> +++ b/gcc/config/riscv/riscv.cc
> @@ -3753,7 +3753,7 @@ riscv_rtx_costs (rtx x, machine_mode mode, int
> outer_code, int opno ATTRIBUTE_UN
>      case MULT:
>        if (float_mode_p)
>         *total = tune_param->fp_mul[mode == DFmode];
> -      else if (!TARGET_MUL)
> +      else if (!(TARGET_MUL || TARGET_ZMMUL))
>         /* Estimate the cost of a library call.  */
>         *total = COSTS_N_INSNS (speed ? 32 : 6);
>        else if (GET_MODE_SIZE (mode).to_constant () > UNITS_PER_WORD)
> diff --git a/gcc/testsuite/gcc.target/riscv/zmmul-3.c
> b/gcc/testsuite/gcc.target/riscv/zmmul-3.c
> new file mode 100644
> index 00000000000..ae9752462e4
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/riscv/zmmul-3.c
> @@ -0,0 +1,8 @@
> +/* { dg-do compile } */
> +/* { dg-options "-march=rv64iafdc_zmmul -mabi=lp64d" } */
> +int foo1(int a)
> +{
> +    return a * 999999;
> +}
> +
> +/* { dg-final { scan-assembler-times "mulw\t" 1 } } */
> \ No newline at end of file
> --
> 2.34.1
>
>