From: Noah Goldstein <goldstein.w.n@gmail.com>
To: libc-alpha@sourceware.org
Cc: goldstein.w.n@gmail.com, hjl.tools@gmail.com, carlos@systemhalted.org
Subject: [PATCH v1 4/4] x86: Use `testb` for FSRM check in memmove-vec-unaligned-erms
Date: Wed, 19 Oct 2022 19:13:38 -0700 [thread overview]
Message-ID: <20221020021338.3394281-4-goldstein.w.n@gmail.com> (raw)
In-Reply-To: <20221020021338.3394281-1-goldstein.w.n@gmail.com>
`testb` saves a bit of code size is the imm-operand can be encoded
1-bytes.
Tested on x86-64.
---
sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S b/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S
index 5b758cae5e..f6d7f3e88b 100644
--- a/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S
+++ b/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S
@@ -616,7 +616,11 @@ L(movsb):
jae L(large_memcpy_2x_check)
# if AVOID_SHORT_DISTANCE_REP_MOVSB || ALIGN_MOVSB
/* Only avoid short movsb if CPU has FSRM. */
+# if X86_STRING_CONTROL_AVOID_SHORT_DISTANCE_REP_MOVSB < 256
+ testb $X86_STRING_CONTROL_AVOID_SHORT_DISTANCE_REP_MOVSB, __x86_string_control(%rip)
+# else
testl $X86_STRING_CONTROL_AVOID_SHORT_DISTANCE_REP_MOVSB, __x86_string_control(%rip)
+# endif
jz L(skip_short_movsb_check)
# if AVOID_SHORT_DISTANCE_REP_MOVSB
/* Avoid "rep movsb" if RCX, the distance between source and
--
2.34.1
next prev parent reply other threads:[~2022-10-20 2:14 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-20 2:13 [PATCH v1 1/4] x86: Use `testb` for case-locale check in str{n}casecmp-avx2 Noah Goldstein
2022-10-20 2:13 ` [PATCH v1 2/4] x86: Use `testb` for case-locale check in str{n}casecmp-sse2 Noah Goldstein
2022-10-20 17:03 ` H.J. Lu
2022-10-20 2:13 ` [PATCH v1 3/4] x86: Use `testb` for case-locale check in str{n}casecmp-sse42 Noah Goldstein
2022-10-20 17:03 ` H.J. Lu
2022-10-20 2:13 ` Noah Goldstein [this message]
2022-10-20 17:03 ` [PATCH v1 4/4] x86: Use `testb` for FSRM check in memmove-vec-unaligned-erms H.J. Lu
2022-10-20 17:02 ` [PATCH v1 1/4] x86: Use `testb` for case-locale check in str{n}casecmp-avx2 H.J. Lu
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