From ee005e72f5fbd258262a93499bdd49a60c0f9714 Mon Sep 17 00:00:00 2001 From: Li Wei Date: Thu, 11 Jan 2024 19:36:33 +0800 Subject: [PATCH] LoongArch: Redundant sign extension elimination optimization 2. Eliminate the redundant sign extension that exists after the conditional move when the target register is SImode. gcc/ChangeLog: * config/loongarch/loongarch.cc (loongarch_expand_conditional_move): Adjust. gcc/testsuite/ChangeLog: * gcc.target/loongarch/sign-extend-2.c: Adjust. --- gcc/config/loongarch/loongarch.cc | 6 ++++++ gcc/testsuite/gcc.target/loongarch/sign-extend-2.c | 5 +++-- 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/gcc/config/loongarch/loongarch.cc b/gcc/config/loongarch/loongarch.cc index 27435aa5b50..3b8559bfdc8 100644 --- a/gcc/config/loongarch/loongarch.cc +++ b/gcc/config/loongarch/loongarch.cc @@ -5371,6 +5371,12 @@ loongarch_expand_conditional_move (rtx *operands) rtx temp3 = gen_reg_rtx (mode); emit_insn (gen_rtx_SET (temp3, gen_rtx_IOR (mode, temp, temp2))); temp3 = gen_lowpart (GET_MODE (operands[0]), temp3); + /* Nonzero in a subreg if it was made when accessing an object that + was promoted to a wider mode in accord with the PROMOTED_MODE + machine description macro. */ + SUBREG_PROMOTED_VAR_P (temp3) = 1; + /* Sets promoted mode for SUBREG_PROMOTED_VAR_P. */ + SUBREG_PROMOTED_SET (temp3, SRP_SIGNED); loongarch_emit_move (operands[0], temp3); } else diff --git a/gcc/testsuite/gcc.target/loongarch/sign-extend-2.c b/gcc/testsuite/gcc.target/loongarch/sign-extend-2.c index a45dde4f73f..e57a2727d0c 100644 --- a/gcc/testsuite/gcc.target/loongarch/sign-extend-2.c +++ b/gcc/testsuite/gcc.target/loongarch/sign-extend-2.c @@ -1,6 +1,7 @@ /* { dg-do compile } */ -/* { dg-options "-mabi=lp64d -O2" } */ -/* { dg-final { scan-assembler-times "slli.w\t\\\$r\[0-9\]+,\\\$r\[0-9\]+,0" 1 } } */ +/* { dg-options "-mabi=lp64d -O2 -fdump-rtl-expand" } */ +/* { dg-final { scan-rtl-dump "subreg/s" "expand" } } */ +/* { dg-final { scan-assembler-not "slli.w\t\\\$r\[0-9\]+,\\\$r\[0-9\]+,0" } } */ #include #define my_min(x, y) ((x) < (y) ? (x) : (y))