https://gcc.gnu.org/g:c38dbfc1ce7e827c4386c4b2595a5327a92b89d2

commit r14-10468-gc38dbfc1ce7e827c4386c4b2595a5327a92b89d2
Author: Liao Shihua <shi...@iscas.ac.cn>
Date:   Fri May 24 13:03:57 2024 +0800

    RISC-V: Fix missing boolean_expression in zmmul extension
    
    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.
    
    (cherry picked from commit 06bb125521dec5648b725ddee4345b00decfdc77)

Diff:
---
 gcc/config/riscv/riscv.cc                | 2 +-
 gcc/testsuite/gcc.target/riscv/zmmul-3.c | 8 ++++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index 1c72a3f616a4..2841787d93e7 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -3598,7 +3598,7 @@ 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 000000000000..f8377f861809
--- /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 } } */

Reply via email to