[llvm] 6cf4f25 - Revert "GlobalISel: Use & operator on KnownBits"

[Matt Arsenault via llvm-commits]

Author: Matt Arsenault
Date: 2020-08-27T18:52:34-04:00
New Revision: 6cf4f256701de964dc540f18dfadce5bd49476eb

URL: https://github.com/llvm/llvm-project/commit/6cf4f256701de964dc540f18dfadce5bd49476eb
DIFF: https://github.com/llvm/llvm-project/commit/6cf4f256701de964dc540f18dfadce5bd49476eb.diff

LOG: Revert "GlobalISel: Use & operator on KnownBits"

This reverts commit e53b799779b079a70f600e5cad2ab7267d66b1b7.

Confusingly, this does not simply and the two sets of known bits, but
implements known bits for the and operator.

Added: 
    

Modified: 
    llvm/lib/CodeGen/GlobalISel/GISelKnownBits.cpp

Removed: 
    


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diff  --git a/llvm/lib/CodeGen/GlobalISel/GISelKnownBits.cpp b/llvm/lib/CodeGen/GlobalISel/GISelKnownBits.cpp
index 2ffbde6a62c4..3552abe998e0 100644
--- a/llvm/lib/CodeGen/GlobalISel/GISelKnownBits.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/GISelKnownBits.cpp
@@ -110,7 +110,8 @@ void GISelKnownBits::computeKnownBitsMin(Register Src0, Register Src1,
   computeKnownBitsImpl(Src0, Known2, DemandedElts, Depth);
 
   // Only known if known in both the LHS and RHS.
-  Known &= Known2;
+  Known.Zero &= Known.Zero;
+  Known.One &= Known.One;
 }
 
 void GISelKnownBits::computeKnownBitsImpl(Register R, KnownBits &Known,