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Commit 918ccb64 authored by Simon Pilgrim's avatar Simon Pilgrim
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[X86][SSE] Handle basic inversion of PTEST/TESTP operands (PR38522)

PTEST/TESTP sets EFLAGS as:
TESTZ: ZF = (Op0 & Op1) == 0
TESTC: CF = (~Op0 & Op1) == 0
TESTNZC: ZF == 0 && CF == 0

If we are inverting the 0'th operand of a PTEST/TESTP instruction we can adjust the comparisons to correct handle the inversion implicitly.

Additionally, for "TESTZ" (ZF) cases, the allones case, PTEST(X,-1) can be simplified to PTEST(X,X).

We can expand this for the TESTZ(X,~Y) pattern and also handle KTEST/KORTEST in the future.

Differential Revision: https://reviews.llvm.org/D76984
parent 8b8cd150
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