diff --git a/llvm/lib/Transforms/Scalar/SCCP.cpp b/llvm/lib/Transforms/Scalar/SCCP.cpp
--- a/llvm/lib/Transforms/Scalar/SCCP.cpp
+++ b/llvm/lib/Transforms/Scalar/SCCP.cpp
@@ -67,10 +67,15 @@
STATISTIC(NumInstRemoved, "Number of instructions removed");
STATISTIC(NumDeadBlocks , "Number of basic blocks unreachable");
+STATISTIC(NumInstReplaced,
+ "Number of instructions replaced with (simpler) instruction");
STATISTIC(IPNumInstRemoved, "Number of instructions removed by IPSCCP");
STATISTIC(IPNumArgsElimed ,"Number of arguments constant propagated by IPSCCP");
STATISTIC(IPNumGlobalConst, "Number of globals found to be constant by IPSCCP");
+STATISTIC(
+ IPNumInstReplaced,
+ "Number of instructions replaced with (simpler) instruction by IPSCCP");
// The maximum number of range extensions allowed for operations requiring
// widening.
@@ -283,6 +288,8 @@
return StructValues;
}
+ void removeLatticeValueFor(Value *V) { ValueState.erase(V); }
+
const ValueLatticeElement &getLatticeValueFor(Value *V) const {
assert(!V->getType()->isStructTy() &&
"Should use getStructLatticeValueFor");
@@ -1607,7 +1614,9 @@
}
static bool simplifyInstsInBlock(SCCPSolver &Solver, BasicBlock &BB,
- Statistic &InstRemovedStat) {
+ SmallPtrSetImpl<Value *> &InsertedValues,
+ Statistic &InstRemovedStat,
+ Statistic &InstReplacedStat) {
bool MadeChanges = false;
for (Instruction &Inst : make_early_inc_range(BB)) {
if (Inst.getType()->isVoidTy())
@@ -1618,6 +1627,22 @@
// Hey, we just changed something!
MadeChanges = true;
++InstRemovedStat;
+ } else if (isa<SExtInst>(&Inst)) {
+ Value *ExtOp = Inst.getOperand(0);
+ if (isa<Constant>(ExtOp) || InsertedValues.count(ExtOp))
+ continue;
+ const ValueLatticeElement &IV = Solver.getLatticeValueFor(ExtOp);
+ if (!IV.isConstantRange(/*UndefAllowed=*/false))
+ continue;
+ if (IV.getConstantRange().isAllNonNegative()) {
+ auto *ZExt = new ZExtInst(ExtOp, Inst.getType(), "", &Inst);
+ InsertedValues.insert(ZExt);
+ Inst.replaceAllUsesWith(ZExt);
+ Solver.removeLatticeValueFor(&Inst);
+ Inst.eraseFromParent();
+ InstReplacedStat++;
+ MadeChanges = true;
+ }
}
}
return MadeChanges;
@@ -1653,6 +1678,7 @@
// delete their contents now. Note that we cannot actually delete the blocks,
// as we cannot modify the CFG of the function.
+ SmallPtrSet<Value *, 32> InsertedValues;
for (BasicBlock &BB : F) {
if (!Solver.isBlockExecutable(&BB)) {
LLVM_DEBUG(dbgs() << " BasicBlock Dead:" << BB);
@@ -1664,7 +1690,8 @@
continue;
}
- MadeChanges |= simplifyInstsInBlock(Solver, BB, NumInstRemoved);
+ MadeChanges |= simplifyInstsInBlock(Solver, BB, InsertedValues,
+ NumInstRemoved, NumInstReplaced);
}
return MadeChanges;
@@ -1893,6 +1920,7 @@
}
}
+ SmallPtrSet<Value *, 32> InsertedValues;
for (BasicBlock &BB : F) {
if (!Solver.isBlockExecutable(&BB)) {
LLVM_DEBUG(dbgs() << " BasicBlock Dead:" << BB);
@@ -1905,7 +1933,8 @@
continue;
}
- MadeChanges |= simplifyInstsInBlock(Solver, BB, IPNumInstRemoved);
+ MadeChanges |= simplifyInstsInBlock(Solver, BB, InsertedValues,
+ IPNumInstRemoved, IPNumInstReplaced);
}
DomTreeUpdater DTU = Solver.getDTU(F);
diff --git a/llvm/test/Transforms/SCCP/ip-ranges-casts.ll b/llvm/test/Transforms/SCCP/ip-ranges-casts.ll
--- a/llvm/test/Transforms/SCCP/ip-ranges-casts.ll
+++ b/llvm/test/Transforms/SCCP/ip-ranges-casts.ll
@@ -109,9 +109,9 @@
; x = [100, 301)
define internal i1 @f.sext(i32 %x, i32 %y) {
; CHECK-LABEL: define internal i1 @f.sext(i32 %x, i32 %y) {
-; CHECK-NEXT: %t.1 = sext i32 %x to i64
-; CHECK-NEXT: %c.2 = icmp sgt i64 %t.1, 299
-; CHECK-NEXT: %c.4 = icmp slt i64 %t.1, 101
+; CHECK-NEXT: [[T_1:%.*]] = zext i32 %x to i64
+; CHECK-NEXT: %c.2 = icmp sgt i64 [[T_1]], 299
+; CHECK-NEXT: %c.4 = icmp slt i64 [[T_1]], 101
; CHECK-NEXT: %res.1 = add i1 false, %c.2
; CHECK-NEXT: %res.2 = add i1 %res.1, false
; CHECK-NEXT: %res.3 = add i1 %res.2, %c.4
diff --git a/llvm/test/Transforms/SCCP/ip-ranges-sext.ll b/llvm/test/Transforms/SCCP/ip-ranges-sext.ll
--- a/llvm/test/Transforms/SCCP/ip-ranges-sext.ll
+++ b/llvm/test/Transforms/SCCP/ip-ranges-sext.ll
@@ -105,8 +105,8 @@
define i64 @test5(i32 %x) {
; CHECK-LABEL: @test5(
; CHECK-NEXT: [[P:%.*]] = and i32 [[X:%.*]], 15
-; CHECK-NEXT: [[EXT:%.*]] = sext i32 [[P]] to i64
-; CHECK-NEXT: ret i64 [[EXT]]
+; CHECK-NEXT: [[TMP1:%.*]] = zext i32 [[P]] to i64
+; CHECK-NEXT: ret i64 [[TMP1]]
;
%p = and i32 %x, 15
%ext = sext i32 %p to i64
@@ -126,8 +126,8 @@
define i64 @test7(i16 %x) {
; CHECK-LABEL: @test7(
; CHECK-NEXT: [[P:%.*]] = and i16 [[X:%.*]], 15
-; CHECK-NEXT: [[EXT_1:%.*]] = sext i16 [[P]] to i32
-; CHECK-NEXT: [[EXT_2:%.*]] = sext i32 [[EXT_1]] to i64
+; CHECK-NEXT: [[TMP1:%.*]] = zext i16 [[P]] to i32
+; CHECK-NEXT: [[EXT_2:%.*]] = sext i32 [[TMP1]] to i64
; CHECK-NEXT: ret i64 [[EXT_2]]
;
%p = and i16 %x, 15
diff --git a/llvm/test/Transforms/SCCP/ranges-sext.ll b/llvm/test/Transforms/SCCP/ranges-sext.ll
--- a/llvm/test/Transforms/SCCP/ranges-sext.ll
+++ b/llvm/test/Transforms/SCCP/ranges-sext.ll
@@ -35,8 +35,8 @@
define i64 @test2(i32 %x) {
; CHECK-LABEL: @test2(
; CHECK-NEXT: [[P:%.*]] = and i32 [[X:%.*]], 15
-; CHECK-NEXT: [[EXT:%.*]] = sext i32 [[P]] to i64
-; CHECK-NEXT: ret i64 [[EXT]]
+; CHECK-NEXT: [[TMP1:%.*]] = zext i32 [[P]] to i64
+; CHECK-NEXT: ret i64 [[TMP1]]
;
%p = and i32 %x, 15
%ext = sext i32 %p to i64
@@ -54,8 +54,8 @@
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: [[P:%.*]] = phi i32 [ 0, [[TRUE_1]] ], [ 1, [[TRUE_2]] ], [ 3, [[FALSE]] ]
-; CHECK-NEXT: [[EXT:%.*]] = sext i32 [[P]] to i64
-; CHECK-NEXT: ret i64 [[EXT]]
+; CHECK-NEXT: [[TMP1:%.*]] = zext i32 [[P]] to i64
+; CHECK-NEXT: ret i64 [[TMP1]]
;
br i1 %c.1, label %true.1, label %false
diff --git a/llvm/test/Transforms/SCCP/widening.ll b/llvm/test/Transforms/SCCP/widening.ll
--- a/llvm/test/Transforms/SCCP/widening.ll
+++ b/llvm/test/Transforms/SCCP/widening.ll
@@ -451,7 +451,7 @@
; SCCP-NEXT: [[TMP7:%.*]] = sub i64 3, [[TMP6]]
; SCCP-NEXT: [[TMP8:%.*]] = shl i64 [[TMP7]], 1
; SCCP-NEXT: [[TMP9:%.*]] = trunc i64 [[TMP8]] to i32
-; SCCP-NEXT: [[TMP10:%.*]] = sext i32 [[TMP9]] to i64
+; SCCP-NEXT: [[TMP10:%.*]] = zext i32 [[TMP9]] to i64
; SCCP-NEXT: br label [[BB11:%.*]]
; SCCP: bb11:
; SCCP-NEXT: [[TMP12:%.*]] = phi i64 [ [[TMP10]], [[BB4]] ], [ [[TMP17:%.*]], [[BB18:%.*]] ]
@@ -489,7 +489,7 @@
; IPSCCP-NEXT: [[TMP7:%.*]] = sub i64 3, [[TMP6]]
; IPSCCP-NEXT: [[TMP8:%.*]] = shl i64 [[TMP7]], 1
; IPSCCP-NEXT: [[TMP9:%.*]] = trunc i64 [[TMP8]] to i32
-; IPSCCP-NEXT: [[TMP10:%.*]] = sext i32 [[TMP9]] to i64
+; IPSCCP-NEXT: [[TMP10:%.*]] = zext i32 [[TMP9]] to i64
; IPSCCP-NEXT: br label [[BB11:%.*]]
; IPSCCP: bb11:
; IPSCCP-NEXT: [[TMP12:%.*]] = phi i64 [ [[TMP10]], [[BB4]] ], [ [[TMP17:%.*]], [[BB18:%.*]] ]