[PATCH] D14906: [X86][FMA] Optimize FNEG(FMA) Patterns
Simon Pilgrim via llvm-commits
llvm-commits at lists.llvm.org
Mon Nov 23 06:15:18 PST 2015
RKSimon added inline comments.
Comment at: lib/Target/X86/X86ISelLowering.cpp:13400
@@ -13399,1 +13399,3 @@
+ // If we're negating a FMA node, then we can adjust the
+ // instruction to include the extra negation.
> What we are doing in PerformFMACombine() ? May be we can extend there?
In PerformFMACombine we convert ISD::FMA nodes to the equivalent X86ISD FMADD/FMSUB/FNMADD/FNMSUB nodes based on which inputs are FNEG.
This patch deal with FNEG which has a X86ISD FMA type as its input - we don't have a PerformFNEGCombine but I could move this patch there if you think it necessary.
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