diff options
| author | Lin Sinan <sinan.lin@linux.alibaba.com> | 2023-03-05 16:09:50 +0800 |
|---|---|---|
| committer | Kito Cheng <kito.cheng@sifive.com> | 2023-03-05 16:59:16 +0800 |
| commit | 602cfc746e9e0447221896a3d93608c6db3a89e5 (patch) | |
| tree | 4dabfecbd076403b5e8c639b06f750a2f1cbb766 | |
| parent | 9debb240a4b1a711c0648fd9e4385dbde5ad45fd (diff) | |
| download | gcc-602cfc746e9e0447221896a3d93608c6db3a89e5.zip gcc-602cfc746e9e0447221896a3d93608c6db3a89e5.tar.gz gcc-602cfc746e9e0447221896a3d93608c6db3a89e5.tar.bz2 | |
RISC-V: Allow const0_rtx operand in max/min
Optimize cases that use max[u]/min[u] against a zero constant.
E.g., the case int f(int x) { return x >= 0 ? x : 0; }
the current asm output in rv64gc_zba_zbb
li rtmp,0
max a0,a0,rtmp
could be optimized into
max a0,a0,zero
gcc/ChangeLog:
* config/riscv/bitmanip.md: allow 0 constant in max/min
pattern.
gcc/testsuite/ChangeLog:
* gcc.target/riscv/zbb-min-max-03.c: New test.
| -rw-r--r-- | gcc/config/riscv/bitmanip.md | 4 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.target/riscv/zbb-min-max-03.c | 10 |
2 files changed, 12 insertions, 2 deletions
diff --git a/gcc/config/riscv/bitmanip.md b/gcc/config/riscv/bitmanip.md index 58a86bd..cfdb9eb 100644 --- a/gcc/config/riscv/bitmanip.md +++ b/gcc/config/riscv/bitmanip.md @@ -363,9 +363,9 @@ (define_insn "<bitmanip_optab><mode>3" [(set (match_operand:X 0 "register_operand" "=r") (bitmanip_minmax:X (match_operand:X 1 "register_operand" "r") - (match_operand:X 2 "register_operand" "r")))] + (match_operand:X 2 "reg_or_0_operand" "rJ")))] "TARGET_ZBB" - "<bitmanip_insn>\t%0,%1,%2" + "<bitmanip_insn>\t%0,%1,%z2" [(set_attr "type" "bitmanip")]) ;; Optimize the common case of a SImode min/max against a constant diff --git a/gcc/testsuite/gcc.target/riscv/zbb-min-max-03.c b/gcc/testsuite/gcc.target/riscv/zbb-min-max-03.c new file mode 100644 index 0000000..c7de100 --- /dev/null +++ b/gcc/testsuite/gcc.target/riscv/zbb-min-max-03.c @@ -0,0 +1,10 @@ +/* { dg-do compile } */ +/* { dg-options "-march=rv64gc_zba_zbb -mabi=lp64d" } */ +/* { dg-skip-if "" { *-*-* } { "-O0" } } */ + +int f(int x) { + return x >= 0 ? x : 0; +} + +/* { dg-final { scan-assembler-times "max\t" 1 } } */ +/* { dg-final { scan-assembler-not "li\t" } } */ |