[GISel]: Add GISelKnownBits analysis
https://reviews.llvm.org/D65698
This adds a KnownBits analysis pass for GISel. This was done as a
pass (compared to static functions) so that we can add other features
such as caching queries(within a pass and across passes) in the future.
This patch only adds the basic pass boiler plate, and implements a lazy
non caching knownbits implementation (ported from SelectionDAG). I've
also hooked up the AArch64PreLegalizerCombiner pass to use this - there
should be no compile time regression as the analysis is lazy.
llvm-svn: 368065
diff --git a/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
index 9149813..18ea45e 100644
--- a/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
@@ -8,6 +8,7 @@
#include "llvm/CodeGen/GlobalISel/CombinerHelper.h"
#include "llvm/CodeGen/GlobalISel/Combiner.h"
#include "llvm/CodeGen/GlobalISel/GISelChangeObserver.h"
+#include "llvm/CodeGen/GlobalISel/GISelKnownBits.h"
#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
#include "llvm/CodeGen/GlobalISel/Utils.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
@@ -22,8 +23,11 @@
using namespace llvm;
CombinerHelper::CombinerHelper(GISelChangeObserver &Observer,
- MachineIRBuilder &B)
- : Builder(B), MRI(Builder.getMF().getRegInfo()), Observer(Observer) {}
+ MachineIRBuilder &B, GISelKnownBits *KB)
+ : Builder(B), MRI(Builder.getMF().getRegInfo()), Observer(Observer),
+ KB(KB) {
+ (void)this->KB;
+}
void CombinerHelper::replaceRegWith(MachineRegisterInfo &MRI, Register FromReg,
Register ToReg) const {