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FP compares and TARGET_SSE_MATH
- From: Uros Bizjak <uros at kss-loka dot si>
- To: gcc at gcc dot gnu dot org
- Date: Thu, 23 Dec 2004 12:21:06 +0100
- Subject: FP compares and TARGET_SSE_MATH
Hello!
I would like to ask about FP compares and TARGET_SSE_MATH. Currently,
SSE compares are enabled for TARGET_SSE, but user has no choice on which
instruction set to use. In pentium4 case, resulting ASM code is a
mixture of i387 compares, SSE compares and a lot of register moving to
satisfy register constraints of used insns. I suggest to limit SSE
compares to TARGET_SSE_MATH.
By limiting SSE compares to TARGET_SSE_MATH, two insn sets would be
separated. If someone still wants to use mixed insn set, one can use
TARGET_MIX_SSE_I387 switch. Similar reasoning applies to FP conditional
move patterns and min/max patterns.
Uros.