Update in V2:
Split -shared change into a separate commit and add some documentation
for it.
Bootstrapped and regtested on x86_64-pc-linu-gnu{-m32,}.
Ok of trunk?
Don't add crtfastmath.o for -shared to avoid changing the MXCSR register
when loading a shared library. crtfastmath.o will be used only when
building executables.
PR target/55522
* config/i386/gnu-user-common.h (GNU_USER_TARGET_MATHFILE_SPEC):
Don't add crtfastmath.o for -shared.
* doc/invoke.texi (-shared): Add related documentation.
---
gcc/config/i386/gnu-user-common.h | 2 +-
gcc/doc/invoke.texi | 3 ++-
2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/gcc/config/i386/gnu-user-common.h
b/gcc/config/i386/gnu-user-common.h
index cab9be2bfb7..9910cd64363 100644
--- a/gcc/config/i386/gnu-user-common.h
+++ b/gcc/config/i386/gnu-user-common.h
@@ -47,7 +47,7 @@ along with GCC; see the file COPYING3. If not see
/* Similar to standard GNU userspace, but adding -ffast-math support. */
#define GNU_USER_TARGET_MATHFILE_SPEC \
- "%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \
+ "%{Ofast|ffast-math|funsafe-math-optimizations:%{!shared:crtfastmath.o%s}} \
%{mpc32:crtprec32.o%s} \
%{mpc64:crtprec64.o%s} \
%{mpc80:crtprec80.o%s}"
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index cb40b38b73a..cba4f19f4f4 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -17656,7 +17656,8 @@ needs to build supplementary stub code for constructors
to work. On
multi-libbed systems, @samp{gcc -shared} must select the correct support
libraries to link against. Failing to supply the correct flags may lead
to subtle defects. Supplying them in cases where they are not necessary
-is innocuous.}
+is innocuous. For x86, crtfastmath.o will not be added when
+@option{-shared} is specified. }
@item -shared-libgcc
@itemx -static-libgcc
--
2.27.0
