[CorrelatedValuePropagation] Mark subs that we know not to wrap with nuw/nsw.
Summary:
Teach CorrelatedValuePropagation to also handle sub instructions in addition to add. Relatively simple since makeGuaranteedNoWrapRegion already understood sub instructions. Only subtle change is which range is passed as "Other" to that function, since sub isn't commutative.
Note that CorrelatedValuePropagation::processAddSub is still hidden behind a default-off flag as IndVarSimplify hasn't yet been fixed to strip the added nsw/nuw flags and causes a miscompile. (PR31181)
Reviewers: sanjoy, apilipenko, nikic
Reviewed By: nikic
Subscribers: hiraditya, jfb, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60036
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358816 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp b/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
index a56a37a..2c31e4a 100644
--- a/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
+++ b/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
@@ -64,7 +64,7 @@
STATISTIC(NumSRems, "Number of srem converted to urem");
STATISTIC(NumOverflows, "Number of overflow checks removed");
-static cl::opt<bool> DontProcessAdds("cvp-dont-process-adds", cl::init(true));
+static cl::opt<bool> DontAddNoWrapFlags("cvp-dont-add-nowrap-flags", cl::init(true));
namespace {
@@ -607,53 +607,53 @@
return true;
}
-static bool processAdd(BinaryOperator *AddOp, LazyValueInfo *LVI) {
+static bool processBinOp(BinaryOperator *BinOp, LazyValueInfo *LVI) {
using OBO = OverflowingBinaryOperator;
- if (DontProcessAdds)
+ if (DontAddNoWrapFlags)
return false;
- if (AddOp->getType()->isVectorTy())
+ if (BinOp->getType()->isVectorTy())
return false;
- bool NSW = AddOp->hasNoSignedWrap();
- bool NUW = AddOp->hasNoUnsignedWrap();
+ bool NSW = BinOp->hasNoSignedWrap();
+ bool NUW = BinOp->hasNoUnsignedWrap();
if (NSW && NUW)
return false;
- BasicBlock *BB = AddOp->getParent();
+ BasicBlock *BB = BinOp->getParent();
- Value *LHS = AddOp->getOperand(0);
- Value *RHS = AddOp->getOperand(1);
+ Value *LHS = BinOp->getOperand(0);
+ Value *RHS = BinOp->getOperand(1);
- ConstantRange LRange = LVI->getConstantRange(LHS, BB, AddOp);
+ ConstantRange RRange = LVI->getConstantRange(RHS, BB, BinOp);
- // Initialize RRange only if we need it. If we know that guaranteed no wrap
- // range for the given LHS range is empty don't spend time calculating the
- // range for the RHS.
- Optional<ConstantRange> RRange;
- auto LazyRRange = [&] () {
- if (!RRange)
- RRange = LVI->getConstantRange(RHS, BB, AddOp);
- return RRange.getValue();
+ // Initialize LRange only if we need it. If we know that guaranteed no wrap
+ // range for the given RHS range is empty don't spend time calculating the
+ // range for the LHS.
+ Optional<ConstantRange> LRange;
+ auto LazyLRange = [&] () {
+ if (!LRange)
+ LRange = LVI->getConstantRange(LHS, BB, BinOp);
+ return LRange.getValue();
};
bool Changed = false;
if (!NUW) {
ConstantRange NUWRange = ConstantRange::makeGuaranteedNoWrapRegion(
- BinaryOperator::Add, LRange, OBO::NoUnsignedWrap);
+ BinOp->getOpcode(), RRange, OBO::NoUnsignedWrap);
if (!NUWRange.isEmptySet()) {
- bool NewNUW = NUWRange.contains(LazyRRange());
- AddOp->setHasNoUnsignedWrap(NewNUW);
+ bool NewNUW = NUWRange.contains(LazyLRange());
+ BinOp->setHasNoUnsignedWrap(NewNUW);
Changed |= NewNUW;
}
}
if (!NSW) {
ConstantRange NSWRange = ConstantRange::makeGuaranteedNoWrapRegion(
- BinaryOperator::Add, LRange, OBO::NoSignedWrap);
+ BinOp->getOpcode(), RRange, OBO::NoSignedWrap);
if (!NSWRange.isEmptySet()) {
- bool NewNSW = NSWRange.contains(LazyRRange());
- AddOp->setHasNoSignedWrap(NewNSW);
+ bool NewNSW = NSWRange.contains(LazyLRange());
+ BinOp->setHasNoSignedWrap(NewNSW);
Changed |= NewNSW;
}
}
@@ -729,7 +729,8 @@
BBChanged |= processAShr(cast<BinaryOperator>(II), LVI);
break;
case Instruction::Add:
- BBChanged |= processAdd(cast<BinaryOperator>(II), LVI);
+ case Instruction::Sub:
+ BBChanged |= processBinOp(cast<BinaryOperator>(II), LVI);
break;
}
}
diff --git a/test/Transforms/CorrelatedValuePropagation/add.ll b/test/Transforms/CorrelatedValuePropagation/add.ll
index 4001f51..026af75 100644
--- a/test/Transforms/CorrelatedValuePropagation/add.ll
+++ b/test/Transforms/CorrelatedValuePropagation/add.ll
@@ -1,4 +1,4 @@
-; RUN: opt < %s -correlated-propagation -cvp-dont-process-adds=false -S | FileCheck %s
+; RUN: opt < %s -correlated-propagation -cvp-dont-add-nowrap-flags=false -S | FileCheck %s
; CHECK-LABEL: @test0(
define void @test0(i32 %a) {
diff --git a/test/Transforms/CorrelatedValuePropagation/sub.ll b/test/Transforms/CorrelatedValuePropagation/sub.ll
index 83f6ff1..6e954e8 100644
--- a/test/Transforms/CorrelatedValuePropagation/sub.ll
+++ b/test/Transforms/CorrelatedValuePropagation/sub.ll
@@ -1,5 +1,5 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt < %s -correlated-propagation -cvp-dont-process-adds=false -S | FileCheck %s
+; RUN: opt < %s -correlated-propagation -cvp-dont-add-nowrap-flags=false -S | FileCheck %s
define void @test0(i32 %a) {
; CHECK-LABEL: @test0(
@@ -7,7 +7,7 @@
; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i32 [[A:%.*]], 100
; CHECK-NEXT: br i1 [[CMP]], label [[BB:%.*]], label [[EXIT:%.*]]
; CHECK: bb:
-; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[A]], 1
+; CHECK-NEXT: [[SUB:%.*]] = sub nuw nsw i32 [[A]], 1
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void
@@ -30,7 +30,7 @@
; CHECK-NEXT: [[CMP:%.*]] = icmp ugt i32 [[A:%.*]], 100
; CHECK-NEXT: br i1 [[CMP]], label [[BB:%.*]], label [[EXIT:%.*]]
; CHECK: bb:
-; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[A]], 1
+; CHECK-NEXT: [[SUB:%.*]] = sub nuw i32 [[A]], 1
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void
@@ -76,7 +76,7 @@
; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i32 [[A:%.*]], -1
; CHECK-NEXT: br i1 [[CMP]], label [[BB:%.*]], label [[EXIT:%.*]]
; CHECK: bb:
-; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[A]], 1
+; CHECK-NEXT: [[SUB:%.*]] = sub nsw i32 [[A]], 1
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void
@@ -99,7 +99,7 @@
; CHECK-NEXT: [[CMP:%.*]] = icmp ugt i32 [[A:%.*]], 2147483647
; CHECK-NEXT: br i1 [[CMP]], label [[BB:%.*]], label [[EXIT:%.*]]
; CHECK: bb:
-; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[A]], 1
+; CHECK-NEXT: [[SUB:%.*]] = sub nuw i32 [[A]], 1
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void
@@ -163,7 +163,7 @@
; CHECK-NEXT: [[CMP:%.*]] = and i1 [[CMP_1]], [[FLAG:%.*]]
; CHECK-NEXT: br i1 [[CMP]], label [[BB:%.*]], label [[EXIT:%.*]]
; CHECK: bb:
-; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[A]], 1
+; CHECK-NEXT: [[SUB:%.*]] = sub nuw i32 [[A]], 1
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void
@@ -191,7 +191,7 @@
; CHECK-NEXT: [[CMP:%.*]] = and i1 [[CMP_1]], [[CMP_2]]
; CHECK-NEXT: br i1 [[CMP]], label [[BB:%.*]], label [[EXIT:%.*]]
; CHECK: bb:
-; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[A]], 1
+; CHECK-NEXT: [[SUB:%.*]] = sub nuw nsw i32 [[A]], 1
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void
@@ -250,7 +250,7 @@
; CHECK-NEXT: [[CMP:%.*]] = and i1 [[CMP_1]], [[CMP_3]]
; CHECK-NEXT: br i1 [[CMP]], label [[BB:%.*]], label [[EXIT:%.*]]
; CHECK: bb:
-; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[A]], 1
+; CHECK-NEXT: [[SUB:%.*]] = sub nuw nsw i32 [[A]], 1
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void
@@ -279,7 +279,7 @@
; CHECK-NEXT: [[CMP:%.*]] = and i1 [[CMP_1]], [[FLAG:%.*]]
; CHECK-NEXT: br i1 [[CMP]], label [[BB:%.*]], label [[EXIT:%.*]]
; CHECK: bb:
-; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[A]], 1
+; CHECK-NEXT: [[SUB:%.*]] = sub nsw i32 [[A]], 1
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void
@@ -307,7 +307,7 @@
; CHECK-NEXT: [[WITHIN:%.*]] = and i1 [[WITHIN_1]], [[WITHIN_2]]
; CHECK-NEXT: br i1 [[WITHIN]], label [[THEN:%.*]], label [[ELSE:%.*]]
; CHECK: then:
-; CHECK-NEXT: [[I_MINUS_6:%.*]] = sub i32 [[I]], 6
+; CHECK-NEXT: [[I_MINUS_6:%.*]] = sub nuw nsw i32 [[I]], 6
; CHECK-NEXT: ret i32 [[I_MINUS_6]]
; CHECK: else:
; CHECK-NEXT: ret i32 0
@@ -336,7 +336,7 @@
; CHECK-NEXT: [[CMP:%.*]] = or i1 [[CMP_1]], [[FLAG:%.*]]
; CHECK-NEXT: br i1 [[CMP]], label [[EXIT:%.*]], label [[BB:%.*]]
; CHECK: bb:
-; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[A]], 1
+; CHECK-NEXT: [[SUB:%.*]] = sub nsw i32 [[A]], 1
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void
@@ -364,7 +364,7 @@
; CHECK-NEXT: [[CMP:%.*]] = or i1 [[CMP_1]], [[CMP_2]]
; CHECK-NEXT: br i1 [[CMP]], label [[EXIT:%.*]], label [[BB:%.*]]
; CHECK: bb:
-; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[A]], 1
+; CHECK-NEXT: [[SUB:%.*]] = sub nuw nsw i32 [[A]], 1
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void
@@ -423,7 +423,7 @@
; CHECK-NEXT: [[CMP:%.*]] = or i1 [[CMP_1]], [[CMP_3]]
; CHECK-NEXT: br i1 [[CMP]], label [[EXIT:%.*]], label [[BB:%.*]]
; CHECK: bb:
-; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[A]], 1
+; CHECK-NEXT: [[SUB:%.*]] = sub nuw nsw i32 [[A]], 1
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void
@@ -452,7 +452,7 @@
; CHECK-NEXT: [[CMP:%.*]] = or i1 [[CMP_1]], [[FLAG:%.*]]
; CHECK-NEXT: br i1 [[CMP]], label [[EXIT:%.*]], label [[BB:%.*]]
; CHECK: bb:
-; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[A]], 1
+; CHECK-NEXT: [[SUB:%.*]] = sub nsw i32 [[A]], 1
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void
@@ -483,7 +483,7 @@
; CHECK-NEXT: [[X:%.*]] = load atomic i32, i32* [[A:%.*]] unordered, align 8
; CHECK-NEXT: fence acquire
; CHECK-NEXT: [[ACC_CURR]] = sub i32 [[ACC]], [[X]]
-; CHECK-NEXT: [[IV_NEXT]] = sub i32 [[IV]], -1
+; CHECK-NEXT: [[IV_NEXT]] = sub nsw i32 [[IV]], -1
; CHECK-NEXT: [[NVAL:%.*]] = load atomic i32, i32* [[N:%.*]] unordered, align 8
; CHECK-NEXT: [[CMP:%.*]] = icmp slt i32 [[IV_NEXT]], [[NVAL]]
; CHECK-NEXT: br i1 [[CMP]], label [[LOOP]], label [[EXIT:%.*]]
@@ -514,7 +514,7 @@
; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i32 [[A:%.*]], 100
; CHECK-NEXT: br i1 [[CMP]], label [[BB:%.*]], label [[EXIT:%.*]]
; CHECK: bb:
-; CHECK-NEXT: [[SUB:%.*]] = sub i32 1, [[A]]
+; CHECK-NEXT: [[SUB:%.*]] = sub nsw i32 1, [[A]]
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void
@@ -537,7 +537,7 @@
; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i32 [[A:%.*]], 10000
; CHECK-NEXT: br i1 [[CMP]], label [[BB:%.*]], label [[EXIT:%.*]]
; CHECK: bb:
-; CHECK-NEXT: [[SUB:%.*]] = sub i32 -2, [[A]]
+; CHECK-NEXT: [[SUB:%.*]] = sub nuw i32 -2, [[A]]
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void
@@ -560,7 +560,7 @@
; CHECK-NEXT: [[CMP:%.*]] = icmp ult i32 [[A:%.*]], 100
; CHECK-NEXT: br i1 [[CMP]], label [[BB:%.*]], label [[EXIT:%.*]]
; CHECK: bb:
-; CHECK-NEXT: [[SUB:%.*]] = sub i32 -1, [[A]]
+; CHECK-NEXT: [[SUB:%.*]] = sub nuw nsw i32 -1, [[A]]
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void
