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[PATCH 2/8] [i386] Add option -moutline-msabi-xlogues

Adds the option to i386.opt and i386.c and adds documentation to

Signed-off-by: Daniel Santos <>
 gcc/config/i386/i386.c   |  3 ++-
 gcc/config/i386/i386.opt |  5 +++++
 gcc/doc/invoke.texi      | 11 ++++++++++-
 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 05974208a27..9a0dfdc77ba 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -4361,7 +4361,8 @@ ix86_target_string (HOST_WIDE_INT isa, HOST_WIDE_INT isa2,
     { "-mstv",				MASK_STV },
     { "-mavx256-split-unaligned-load",	MASK_AVX256_SPLIT_UNALIGNED_LOAD },
     { "-mavx256-split-unaligned-store",	MASK_AVX256_SPLIT_UNALIGNED_STORE },
-    { "-mprefer-avx128",		MASK_PREFER_AVX128 }
+    { "-mprefer-avx128",		MASK_PREFER_AVX128 },
+    { "-mmoutline-msabi-xlogues",	MASK_OUTLINE_MSABI_XLOGUES }
   /* Additional flag options.  */
diff --git a/gcc/config/i386/i386.opt b/gcc/config/i386/i386.opt
index 0ee31845eba..0ff93f831c0 100644
--- a/gcc/config/i386/i386.opt
+++ b/gcc/config/i386/i386.opt
@@ -538,6 +538,11 @@ Enum(calling_abi) String(sysv) Value(SYSV_ABI)
 Enum(calling_abi) String(ms) Value(MS_ABI)
+Target Report Mask(OUTLINE_MSABI_XLOGUES) Save
+Reduces function size by using out-of-line stubs to save & restore registers
+clobberd by differences in Microsoft and System V ABIs.
 Target RejectNegative Joined Var(ix86_veclibabi_type) Enum(ix86_veclibabi) Init(ix86_veclibabi_type_none)
 Vector library ABI to use.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 4b13aeb7426..901abbf99d6 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -1210,7 +1210,7 @@ See RS/6000 and PowerPC Options.
 -msse2avx  -mfentry  -mrecord-mcount  -mnop-mcount  -m8bit-idiv @gol
 -mavx256-split-unaligned-load  -mavx256-split-unaligned-store @gol
 -malign-data=@var{type}  -mstack-protector-guard=@var{guard} @gol
--mmitigate-rop  -mgeneral-regs-only}
+-mmitigate-rop  -mgeneral-regs-only  -moutline-msabi-xlogues}
 @emph{x86 Windows Options}
 @gccoptlist{-mconsole  -mcygwin  -mno-cygwin  -mdll @gol
@@ -25304,6 +25304,15 @@ You can control this behavior for specific functions by
 using the function attributes @code{ms_abi} and @code{sysv_abi}.
 @xref{Function Attributes}.
+@item -moutline-msabi-xlogues
+@opindex moutline-msabi-xlogues
+@opindex no-moutline-msabi-xlogues
+Due to differences in 64-bit ABIs, any Microsoft ABI function that calls a
+SysV ABI function must consider RSI, RDI and XMM6-15 as clobbered, emitting
+fairly lengthy prologues and epilogues.  This option generates prologues and
+epilogues that instead call stubs in libgcc to perform these saves & restores,
+thus reducing function size at the cost of and few extra instructions.
 @item -mtls-dialect=@var{type}
 @opindex mtls-dialect
 Generate code to access thread-local storage using the @samp{gnu} or

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