[PATCH] D38378: [ARM] Optimize {s,u}{add,sub}.with.overflow.

[Javed Absar via Phabricator via llvm-commits]

javed.absar added inline comments.


================
Comment at: lib/Target/ARM/ARMBaseInstrInfo.cpp:2569
+  if ((CmpI->getOpcode() == ARM::CMPrr || CmpI->getOpcode() == ARM::t2CMPrr) &&
+      (OI->getOpcode() == ARM::ADDrr || OI->getOpcode() == ARM::t2ADDrr ||
+       OI->getOpcode() == ARM::ADDri || OI->getOpcode() == ARM::t2ADDri) &&
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jgalenson wrote:
> javed.absar wrote:
> > Did you mean t2ADDrr in second case? You have two conditions checking for ARM::ADDrr. Same wit ARM::ADDri
> I'm not sure what you mean.  This seems reasonable to me.  I'm using the result and first operand of the add to match the two operands of the compare, so I don't care what the last operand of the add is.  I thus don't care whether it's a register or an immediate, and it can also be either ARM or Thumb.  So don't all four of these cases work?
OK, my bad. I missed out the "t2" on my screen. All good.


https://reviews.llvm.org/D38378