Pushed to r14-5547. 在 2023/11/17 上午10:38, Li Wei 写道:
The LoongArch has defined ctz and clz on the backend, but if we want GCC do CTZ transformation optimization in forwprop2 pass, GCC need to know the value of c[lt]z at zero, which may be beneficial for some test cases (like spec2017 deepsjeng_r).After implementing the macro, we test dynamic instruction count on deepsjeng_r: - before 1688423249186 - after 1660311215745 (1.66% reduction) gcc/ChangeLog: * config/loongarch/loongarch.h (CLZ_DEFINED_VALUE_AT_ZERO): Implement. (CTZ_DEFINED_VALUE_AT_ZERO): Same. gcc/testsuite/ChangeLog: * gcc.dg/pr90838.c: add clz/ctz test support on LoongArch. --- gcc/config/loongarch/loongarch.h | 5 +++++ gcc/testsuite/gcc.dg/pr90838.c | 5 +++++ 2 files changed, 10 insertions(+) diff --git a/gcc/config/loongarch/loongarch.h b/gcc/config/loongarch/loongarch.h index ddac8e98ea9..115222e70fd 100644 --- a/gcc/config/loongarch/loongarch.h +++ b/gcc/config/loongarch/loongarch.h @@ -1239,3 +1239,8 @@ struct GTY (()) machine_function#define TARGET_EXPLICIT_RELOCS \(la_opt_explicit_relocs == EXPLICIT_RELOCS_ALWAYS) + +#define CLZ_DEFINED_VALUE_AT_ZERO(MODE, VALUE) \ + ((VALUE) = GET_MODE_UNIT_BITSIZE (MODE), 2) +#define CTZ_DEFINED_VALUE_AT_ZERO(MODE, VALUE) \ + ((VALUE) = GET_MODE_UNIT_BITSIZE (MODE), 2) diff --git a/gcc/testsuite/gcc.dg/pr90838.c b/gcc/testsuite/gcc.dg/pr90838.c index 759059683a9..40aad70499d 100644 --- a/gcc/testsuite/gcc.dg/pr90838.c +++ b/gcc/testsuite/gcc.dg/pr90838.c @@ -83,3 +83,8 @@ int ctz4 (unsigned long x) /* { dg-final { scan-assembler-times "ctz\t" 3 { target { rv32 } } } } */ /* { dg-final { scan-assembler-times "andi\t" 1 { target { rv32 } } } } */ /* { dg-final { scan-assembler-times "mul\t" 1 { target { rv32 } } } } */ + +/* { dg-final { scan-tree-dump-times {= \.CTZ} 4 "forwprop2" { target { loongarch64*-*-* } } } } */ +/* { dg-final { scan-assembler-times "ctz.d\t" 1 { target { loongarch64*-*-* } } } } */ +/* { dg-final { scan-assembler-times "ctz.w\t" 3 { target { loongarch64*-*-* } } } } */ +/* { dg-final { scan-assembler-times "andi\t" 4 { target { loongarch64*-*-* } } } } */
