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[2/7] Don't disable SSE in x86-64 ld.so

Message ID CAMe9rOoLbnkEJiKQDcNPu=3CRsoraLHbinPnNAd5rXQqXafEWQ@mail.gmail.com
State New
Headers show

Commit Message

H.J. Lu Aug. 25, 2015, 9:30 p.m. UTC 
On Tue, Aug 25, 2015 at 2:08 PM, Roland McGrath <roland@hack.frob.com> wrote:
> I meant comments in sysdeps/i386/Makefile.

Here is the updated patch.  OK for master?

Comments

Roland McGrath Aug. 25, 2015, 9:31 p.m. UTC | #1 
I meant a comment for the CFLAGS-.os setting, but close enough.

However, the x86_64/Makefile bit needs a comment for its CFLAGS-.os
setting that explains why -mno-mmx is necessary in ld.so code.
diff mbox

Patch

From 92ca9e8d613f9f891e12e3e59d7e9a5855cb129c Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Tue, 28 Jul 2015 18:56:18 -0700
Subject: [PATCH] Don't disable SSE in x86-64 ld.so

Since x86-64 ld.so preserves vector registers now, we can use SSE in
x86-64 ld.so.  We should run tst-ld-sse-use.sh only on i386.

	* sysdeps/x86/Makefile [$(subdir) == elf] (CFLAGS-.os,
	tests-special, $(objpfx)tst-ld-sse-use.out): Moved to ...
	* sysdeps/i386/Makefile [$(subdir) == elf] (CFLAGS-.os,
	tests-special, $(objpfx)tst-ld-sse-use.out): Here.  Update
	comments.
	* sysdeps/x86_64/Makefile [$(subdir) == elf] (CFLAGS-.os): Add
	-mno-mmx for $(all-rtld-routines).
	* sysdeps/x86/tst-ld-sse-use.sh: Moved to ...
	* sysdeps/i386/tst-ld-sse-use.sh: Here.  Replace x86-64 with
	i386.
---
 sysdeps/i386/Makefile                   | 14 ++++++++++++++
 sysdeps/{x86 => i386}/tst-ld-sse-use.sh |  2 +-
 sysdeps/x86/Makefile                    | 11 -----------
 sysdeps/x86_64/Makefile                 |  3 +++
 4 files changed, 18 insertions(+), 12 deletions(-)
 rename sysdeps/{x86 => i386}/tst-ld-sse-use.sh (97%)

diff --git a/sysdeps/i386/Makefile b/sysdeps/i386/Makefile
index 717d8e7..4f83c82 100644
--- a/sysdeps/i386/Makefile
+++ b/sysdeps/i386/Makefile
@@ -83,3 +83,17 @@  endif
 ifeq ($(subdir),csu)
 gen-as-const-headers += tlsdesc.sym
 endif
+
+ifeq ($(subdir),elf)
+CFLAGS-.os += $(if $(filter $(@F),$(patsubst %,%.os,$(all-rtld-routines))),\
+		   -mno-sse -mno-mmx)
+
+tests-special += $(objpfx)tst-ld-sse-use.out
+# Make sure no code in ld.so uses xmm/ymm/zmm registers on i386 since
+# the first 3 xmm/ymm/zmm registers are used to pass vector parameters
+# which must be preserved.
+$(objpfx)tst-ld-sse-use.out: ../sysdeps/i386/tst-ld-sse-use.sh $(objpfx)ld.so
+	@echo "Checking ld.so for SSE register use.  This will take a few seconds..."
+	$(BASH) $< $(objpfx) '$(NM)' '$(OBJDUMP)' '$(READELF)' > $@; \
+	$(evaluate-test)
+endif
diff --git a/sysdeps/x86/tst-ld-sse-use.sh b/sysdeps/i386/tst-ld-sse-use.sh
similarity index 97%
rename from sysdeps/x86/tst-ld-sse-use.sh
rename to sysdeps/i386/tst-ld-sse-use.sh
index 839de18..85a0651 100755
--- a/sysdeps/x86/tst-ld-sse-use.sh
+++ b/sysdeps/i386/tst-ld-sse-use.sh
@@ -1,5 +1,5 @@ 
 #! /bin/bash
-# Make sure no code in ld.so uses xmm/ymm/zmm registers on x86-64.
+# Make sure no code in ld.so uses xmm/ymm/zmm registers on i386.
 # Copyright (C) 2009-2015 Free Software Foundation, Inc.
 # This file is part of the GNU C Library.
 
diff --git a/sysdeps/x86/Makefile b/sysdeps/x86/Makefile
index c262fdf..0de4f42 100644
--- a/sysdeps/x86/Makefile
+++ b/sysdeps/x86/Makefile
@@ -1,14 +1,3 @@ 
-ifeq ($(subdir),elf)
-CFLAGS-.os += $(if $(filter $(@F),$(patsubst %,%.os,$(all-rtld-routines))),\
-		   -mno-sse -mno-mmx)
-
-tests-special += $(objpfx)tst-ld-sse-use.out
-$(objpfx)tst-ld-sse-use.out: ../sysdeps/x86/tst-ld-sse-use.sh $(objpfx)ld.so
-	@echo "Checking ld.so for SSE register use.  This will take a few seconds..."
-	$(BASH) $< $(objpfx) '$(NM)' '$(OBJDUMP)' '$(READELF)' > $@; \
-	$(evaluate-test)
-endif
-
 ifeq ($(subdir),csu)
 gen-as-const-headers += cpu-features-offsets.sym rtld-global-offsets.sym
 endif
diff --git a/sysdeps/x86_64/Makefile b/sysdeps/x86_64/Makefile
index e50bcad..7bcfd87 100644
--- a/sysdeps/x86_64/Makefile
+++ b/sysdeps/x86_64/Makefile
@@ -19,6 +19,9 @@  gen-as-const-headers += locale-defines.sym
 endif
 
 ifeq ($(subdir),elf)
+CFLAGS-.os += $(if $(filter $(@F),$(patsubst %,%.os,$(all-rtld-routines))),\
+		   -mno-mmx)
+
 sysdep-dl-routines += tlsdesc dl-tlsdesc
 
 tests += ifuncmain8
-- 
2.4.3