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why are multiply-accumulate insns not used when -mfp32 on mips
- From: "Amker.Cheng" <amker dot cheng at gmail dot com>
- To: gcc at gcc dot gnu dot org
- Date: Wed, 21 Jul 2010 14:10:36 +0800
- Subject: why are multiply-accumulate insns not used when -mfp32 on mips
HI:
found mult-acc insns like madd.s/d are only used when -mfp64 is specified,
as to codes, there macros defined as:
#define ISA_HAS_FP4 ((ISA_MIPS4 \
|| (ISA_MIPS32R2 && TARGET_FLOAT64) \ <------only float 64
|| ISA_MIPS64 \
|| ISA_MIPS64R2) \
&& !TARGET_MIPS16)
#define ISA_HAS_FP_MADD4_MSUB4 ISA_HAS_FP4
why not use madd when fp32? Is there anything special with fp32?
any clarification? Thanks very much
--
Best Regards.