The new behaviour of the GCC driver passing floating point options
like -msoft-float to the assembler is essential for the new o32 ABI
extensions but is a change in behaviour. In particular GCC 5 used with
binutils 2.24 would require a user to fix any hand-crafted code that
made use of floating-point instructions when building for soft-float.
This patch limits the new behaviour to a combination of GCC and
binutils that both have the new ABI support.
This patch along with parts of several previous patches need backporting
to GCC 4.9 (and GCC 4.8) to enable use of binutils 2.25 with those
compilers. The GCC 4.9 patch will be posted shortly.
Thanks,
Matthew
gcc/
* config/mips/mips.h (FP_ASM_SPEC): New define.
(ASM_SPEC): Remove floating-point options and use FP_ASM_SPEC
instead.
---
gcc/config/mips/mips.h | 21 ++++++++++++++++++---
1 file changed, 18 insertions(+), 3 deletions(-)
diff --git a/gcc/config/mips/mips.h b/gcc/config/mips/mips.h
index 37d4cb4..ed241fa 100644
--- a/gcc/config/mips/mips.h
+++ b/gcc/config/mips/mips.h
@@ -1243,6 +1243,22 @@ struct mips_cpu_info {
%{gcoff*:-mdebug} %{!gcoff*:-no-mdebug}"
#endif
+/* FP_ASM_SPEC represents the floating-point options that must be passed
+ to the assembler when FPXX support exists. Prior to that point the
+ assembler could accept the options but were not required for
+ correctness. We only add the options when absolutely necessary
+ because passing -msoft-float to the assembler will cause it to reject
+ all hard-float instructions which may require some user code to be
+ updated. */
+
+#ifdef HAVE_AS_DOT_MODULE
+#define FP_ASM_SPEC "\
+%{mhard-float} %{msoft-float} \
+%{msingle-float} %{mdouble-float}"
+#else
+#define FP_ASM_SPEC
+#endif
+
/* SUBTARGET_ASM_SPEC is always passed to the assembler. It may be
overridden by subtargets. */
@@ -1277,9 +1293,8 @@ struct mips_cpu_info {
%{modd-spreg} %{mno-odd-spreg} \
%{mshared} %{mno-shared} \
%{msym32} %{mno-sym32} \
-%{mtune=*} \
-%{mhard-float} %{msoft-float} \
-%{msingle-float} %{mdouble-float} \
+%{mtune=*}" \
+FP_ASM_SPEC "\
%(subtarget_asm_spec)"
/* Extra switches sometimes passed to the linker. */
--
2.2.1
