Hello!
Attached patch improves ix86_fixup_binary_operands a bit for the
unlikely situation when both input operands are placed in memory. The
patch forces non-matched operand 1 into register, leaving operand 2 in
memory. Since x86 instruction patterns allow memory operand via
operand 2, the new approach requires less fixups in reload pass.
2013-10-17 Uros Bizjak <ubiz...@gmail.com>
* config/i386/i386.c (ix86_fixup_binary_operands): When both source
operands are in memory, prefer to force non-matched operand 1 to
the register.
Patch was tested on x86_64-pc-linux-gnu {,-m32} and committed to mainline SVN.
Uros.
Index: config/i386/i386.c
===================================================================
--- config/i386/i386.c (revision 203770)
+++ config/i386/i386.c (working copy)
@@ -16897,8 +16897,10 @@ ix86_fixup_binary_operands (enum rtx_code code, en
src2 = force_reg (mode, src2);
src1 = src2;
}
+ else if (rtx_equal_p (dst, src1))
+ src2 = force_reg (mode, src2);
else
- src2 = force_reg (mode, src2);
+ src1 = force_reg (mode, src1);
}
/* If the destination is memory, and we do not have matching source
