On 7/21/23 23:05, Jeff Law wrote:
On 7/21/23 12:30, Vineet Gupta wrote:Fixes: ef85d150b5963 ("RISC-V: Enable TARGET_SUPPORTS_WIDE_INT") (gcc-13 regression)DF +0.0 is bitwise all zeros so int x0 store to mem can be used to optimize it.void zd(double *) { *d = 0.0; } currently: | fmv.d.x fa5,zero | fsd fa5,0(a0) | ret With patch | sd zero,0(a0) | ret This came to light when testing the in-flight f-m-o patch where an ICE was getting triggered due to lack of this pattern but turns out this is an independent optimization of its own [1] [1] https://gcc.gnu.org/pipermail/gcc-patches/2023-July/624857.html Ran thru full multilib testsuite, there was 1 false failure due to random string "lw" appearing in lto build assembler output, which is also fixed in the patch. gcc/Changelog: PR target/110748 * config/riscv/predicates.md (const_0_operand): Add back const_double. gcc/testsuite/ChangeLog: * gcc.target/riscv/pr110748-1.c: New Test. * gcc.target/riscv/xtheadfmv-fmv.c: Add '\t' around test patterns to avoid random string matches.OK jeff
Thx Jeff. I couldn't resist beefing up the changelog some more to capture the technicalities at heart. Hopefully someone in future getting up to speed on gcc will find it informing.
-Vineet
