From: Noah Goldstein Date: Wed, 1 Nov 2023 20:30:26 +0000 (-0500) Subject: x86: Only align destination to 1x VEC_SIZE in memset 4x loop X-Git-Tag: glibc-2.39~238 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9469261cf1924d350feeec64d2c80cafbbdcdd4d;p=thirdparty%2Fglibc.git x86: Only align destination to 1x VEC_SIZE in memset 4x loop Current code aligns to 2x VEC_SIZE. Aligning to 2x has no affect on performance other than potentially resulting in an additional iteration of the loop. 1x maintains aligned stores (the only reason to align in this case) and doesn't incur any unnecessary loop iterations. Reviewed-by: Sunil K Pandey --- diff --git a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S index 3d9ad49cb91..0f0636b90f8 100644 --- a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S +++ b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S @@ -293,7 +293,7 @@ L(more_2x_vec): leaq (VEC_SIZE * 4)(%rax), %LOOP_REG #endif /* Align dst for loop. */ - andq $(VEC_SIZE * -2), %LOOP_REG + andq $(VEC_SIZE * -1), %LOOP_REG .p2align 4 L(loop): VMOVA %VMM(0), LOOP_4X_OFFSET(%LOOP_REG)