[InstCombine][X86] simplifyX86immShift - convert variable in-range vector shift by scalar amounts to generic shifts (PR40391)

The sll/srl/sra scalar vector shifts can be replaced with generic shifts if the shift amount is known to be in range.

This also required public DemandedElts variants of llvm::computeKnownBits to be exposed (PR36319).

1 files changed, 20 insertions, 0 deletions

diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index b7af0d2..773f79c 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -215,6 +215,15 @@ void llvm::computeKnownBits(const Value *V, KnownBits &Known,
                      Query(DL, AC, safeCxtI(V, CxtI), DT, UseInstrInfo, ORE));
 }
 
+void llvm::computeKnownBits(const Value *V, const APInt &DemandedElts,
+                            KnownBits &Known, const DataLayout &DL,
+                            unsigned Depth, AssumptionCache *AC,
+                            const Instruction *CxtI, const DominatorTree *DT,
+                            OptimizationRemarkEmitter *ORE, bool UseInstrInfo) {
+  ::computeKnownBits(V, DemandedElts, Known, Depth,
+                     Query(DL, AC, safeCxtI(V, CxtI), DT, UseInstrInfo, ORE));
+}
+
 static KnownBits computeKnownBits(const Value *V, const APInt &DemandedElts,
                                   unsigned Depth, const Query &Q);
 
@@ -231,6 +240,17 @@ KnownBits llvm::computeKnownBits(const Value *V, const DataLayout &DL,
       V, Depth, Query(DL, AC, safeCxtI(V, CxtI), DT, UseInstrInfo, ORE));
 }
 
+KnownBits llvm::computeKnownBits(const Value *V, const APInt &DemandedElts,
+                                 const DataLayout &DL, unsigned Depth,
+                                 AssumptionCache *AC, const Instruction *CxtI,
+                                 const DominatorTree *DT,
+                                 OptimizationRemarkEmitter *ORE,
+                                 bool UseInstrInfo) {
+  return ::computeKnownBits(
+      V, DemandedElts, Depth,
+      Query(DL, AC, safeCxtI(V, CxtI), DT, UseInstrInfo, ORE));
+}
+
 bool llvm::haveNoCommonBitsSet(const Value *LHS, const Value *RHS,
                                const DataLayout &DL, AssumptionCache *AC,
                                const Instruction *CxtI, const DominatorTree *DT,