This patch has been merged in GCC-14 but it needs to be added into GCC-13 as well.
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. (cherry picked from commit 06bb125521dec5648b725ddee4345b00decfdc77) --- 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 ca3eae2abf3..a3d32c05d3c 100644 --- a/gcc/config/riscv/riscv.cc +++ b/gcc/config/riscv/riscv.cc @@ -2643,7 +2643,7 @@ 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..f8377f86180 --- /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 } } */ -- 2.43.0
