[CVP] After proving that @llvm.with.overflow()/@llvm.sat() don't overflow, also try to prove other no-wrap
Summary:
CVP, unlike InstCombine, does not run till exaustion.
It only does a single pass.
When dealing with those special binops, if we prove that they can
safely be demoted into their usual binop form,
we do set the no-wrap we deduced. But when dealing with usual binops,
we try to deduce both no-wraps.
So if we convert e.g. @llvm.uadd.with.overflow() to `add nuw`,
we won't attempt to check whether it can be `add nuw nsw`.
This patch proposes to call `processBinOp()` on newly-created binop,
which is identical to what we do for div/rem already.
Reviewers: nikic, spatel, reames
Reviewed By: nikic
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D69183
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@375273 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp b/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
index 52a7795..4ed0f2e 100644
--- a/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
+++ b/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
@@ -473,8 +473,10 @@
}
}
+static bool processBinOp(BinaryOperator *BinOp, LazyValueInfo *LVI);
+
// Rewrite this with.overflow intrinsic as non-overflowing.
-static void processOverflowIntrinsic(WithOverflowInst *WO) {
+static void processOverflowIntrinsic(WithOverflowInst *WO, LazyValueInfo *LVI) {
IRBuilder<> B(WO);
Instruction::BinaryOps Opcode = WO->getBinaryOp();
bool NSW = WO->isSigned();
@@ -492,9 +494,13 @@
WO->replaceAllUsesWith(NewI);
WO->eraseFromParent();
++NumOverflows;
+
+ // See if we can infer the other no-wrap too.
+ if (auto *BO = dyn_cast<BinaryOperator>(NewOp))
+ processBinOp(BO, LVI);
}
-static void processSaturatingInst(SaturatingInst *SI) {
+static void processSaturatingInst(SaturatingInst *SI, LazyValueInfo *LVI) {
Instruction::BinaryOps Opcode = SI->getBinaryOp();
bool NSW = SI->isSigned();
bool NUW = !SI->isSigned();
@@ -506,6 +512,10 @@
SI->replaceAllUsesWith(BinOp);
SI->eraseFromParent();
++NumSaturating;
+
+ // See if we can infer the other no-wrap too.
+ if (auto *BO = dyn_cast<BinaryOperator>(BinOp))
+ processBinOp(BO, LVI);
}
/// Infer nonnull attributes for the arguments at the specified callsite.
@@ -515,14 +525,14 @@
if (auto *WO = dyn_cast<WithOverflowInst>(CS.getInstruction())) {
if (WO->getLHS()->getType()->isIntegerTy() && willNotOverflow(WO, LVI)) {
- processOverflowIntrinsic(WO);
+ processOverflowIntrinsic(WO, LVI);
return true;
}
}
if (auto *SI = dyn_cast<SaturatingInst>(CS.getInstruction())) {
if (SI->getType()->isIntegerTy() && willNotOverflow(SI, LVI)) {
- processSaturatingInst(SI);
+ processSaturatingInst(SI, LVI);
return true;
}
}
diff --git a/test/Transforms/CorrelatedValuePropagation/overflows.ll b/test/Transforms/CorrelatedValuePropagation/overflows.ll
index 05c1003..211e63a 100644
--- a/test/Transforms/CorrelatedValuePropagation/overflows.ll
+++ b/test/Transforms/CorrelatedValuePropagation/overflows.ll
@@ -38,7 +38,7 @@
; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i32 [[Y:%.*]], 0
; CHECK-NEXT: br i1 [[CMP]], label [[LAND_LHS_TRUE:%.*]], label [[LOR_LHS_FALSE:%.*]]
; CHECK: land.lhs.true:
-; CHECK-NEXT: [[TMP0:%.*]] = sub nsw i32 2147483647, [[Y]]
+; CHECK-NEXT: [[TMP0:%.*]] = sub nuw nsw i32 2147483647, [[Y]]
; CHECK-NEXT: [[TMP1:%.*]] = insertvalue { i32, i1 } { i32 undef, i1 false }, i32 [[TMP0]], 0
; CHECK-NEXT: [[TMP2:%.*]] = extractvalue { i32, i1 } [[TMP1]], 1
; CHECK-NEXT: br i1 [[TMP2]], label [[TRAP:%.*]], label [[CONT:%.*]]
@@ -116,7 +116,7 @@
define i32 @unsigned_add(i32 %x, i32 %y) {
; CHECK-LABEL: @unsigned_add(
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[TMP0:%.*]] = sub nuw i32 -1, [[Y:%.*]]
+; CHECK-NEXT: [[TMP0:%.*]] = sub nuw nsw i32 -1, [[Y:%.*]]
; CHECK-NEXT: [[TMP1:%.*]] = insertvalue { i32, i1 } { i32 undef, i1 false }, i32 [[TMP0]], 0
; CHECK-NEXT: [[TMP2:%.*]] = extractvalue { i32, i1 } [[TMP1]], 1
; CHECK-NEXT: br i1 [[TMP2]], label [[TRAP:%.*]], label [[CONT:%.*]]
@@ -182,7 +182,7 @@
; CHECK-NEXT: [[CMP2:%.*]] = icmp eq i32 [[Y]], 0
; CHECK-NEXT: br i1 [[CMP2]], label [[COND_FALSE]], label [[LAND_LHS_TRUE3:%.*]]
; CHECK: land.lhs.true3:
-; CHECK-NEXT: [[TMP4:%.*]] = add nsw i32 [[Y]], -2147483648
+; CHECK-NEXT: [[TMP4:%.*]] = add nuw nsw i32 [[Y]], -2147483648
; CHECK-NEXT: [[TMP5:%.*]] = insertvalue { i32, i1 } { i32 undef, i1 false }, i32 [[TMP4]], 0
; CHECK-NEXT: [[TMP6:%.*]] = extractvalue { i32, i1 } [[TMP5]], 1
; CHECK-NEXT: br i1 [[TMP6]], label [[TRAP]], label [[CONT4:%.*]]
@@ -506,7 +506,7 @@
; CHECK-NEXT: [[CMP:%.*]] = icmp ugt i32 [[X:%.*]], 10000
; CHECK-NEXT: br i1 [[CMP]], label [[COND_END:%.*]], label [[COND_FALSE:%.*]]
; CHECK: cond.false:
-; CHECK-NEXT: [[MULO1:%.*]] = mul nuw i32 [[X]], 100
+; CHECK-NEXT: [[MULO1:%.*]] = mul nuw nsw i32 [[X]], 100
; CHECK-NEXT: [[TMP0:%.*]] = insertvalue { i32, i1 } { i32 undef, i1 false }, i32 [[MULO1]], 0
; CHECK-NEXT: [[RES:%.*]] = extractvalue { i32, i1 } [[TMP0]], 0
; CHECK-NEXT: [[OV:%.*]] = extractvalue { i32, i1 } [[TMP0]], 1
@@ -760,7 +760,7 @@
; CHECK-NEXT: call void @llvm.trap()
; CHECK-NEXT: unreachable
; CHECK: cont:
-; CHECK-NEXT: [[RES1:%.*]] = add nuw i8 [[X]], 100
+; CHECK-NEXT: [[RES1:%.*]] = add nuw nsw i8 [[X]], 100
; CHECK-NEXT: ret i8 [[RES1]]
;
%cmp = icmp ugt i8 %x, 27
@@ -806,7 +806,7 @@
; CHECK-NEXT: call void @llvm.trap()
; CHECK-NEXT: unreachable
; CHECK: cont:
-; CHECK-NEXT: [[RES1:%.*]] = add nsw i8 [[X]], 20
+; CHECK-NEXT: [[RES1:%.*]] = add nuw nsw i8 [[X]], 20
; CHECK-NEXT: ret i8 [[RES1]]
;
%cmp = icmp ugt i8 %x, 107
@@ -852,7 +852,7 @@
; CHECK-NEXT: call void @llvm.trap()
; CHECK-NEXT: unreachable
; CHECK: cont:
-; CHECK-NEXT: [[RES1:%.*]] = sub nuw i8 [[X]], 100
+; CHECK-NEXT: [[RES1:%.*]] = sub nuw nsw i8 [[X]], 100
; CHECK-NEXT: ret i8 [[RES1]]
;
%cmp = icmp ult i8 %x, 228
@@ -898,7 +898,7 @@
; CHECK-NEXT: call void @llvm.trap()
; CHECK-NEXT: unreachable
; CHECK: cont:
-; CHECK-NEXT: [[RES1:%.*]] = sub nsw i8 [[X]], 20
+; CHECK-NEXT: [[RES1:%.*]] = sub nuw nsw i8 [[X]], 20
; CHECK-NEXT: ret i8 [[RES1]]
;
%cmp = icmp ult i8 %x, 148
@@ -982,7 +982,7 @@
; CHECK-NEXT: [[CMP2:%.*]] = icmp ult i32 [[Y:%.*]], 10
; CHECK-NEXT: br i1 [[CMP2]], label [[CONT2:%.*]], label [[OUT]]
; CHECK: cont2:
-; CHECK-NEXT: [[RES1:%.*]] = add nuw i32 [[X]], [[Y]]
+; CHECK-NEXT: [[RES1:%.*]] = add nuw nsw i32 [[X]], [[Y]]
; CHECK-NEXT: [[TMP0:%.*]] = insertvalue { i32, i1 } { i32 undef, i1 false }, i32 [[RES1]], 0
; CHECK-NEXT: [[ADD:%.*]] = extractvalue { i32, i1 } [[TMP0]], 0
; CHECK-NEXT: br label [[CONT3:%.*]]
@@ -1023,7 +1023,7 @@
; CHECK-NEXT: br i1 [[CMP2]], label [[CONT2:%.*]], label [[OUT]]
; CHECK: cont2:
; CHECK-NEXT: [[OFFSET:%.*]] = add nuw nsw i32 [[X]], 9
-; CHECK-NEXT: [[RES1:%.*]] = sub nsw i32 [[OFFSET]], [[Y]]
+; CHECK-NEXT: [[RES1:%.*]] = sub nuw nsw i32 [[OFFSET]], [[Y]]
; CHECK-NEXT: [[TMP0:%.*]] = insertvalue { i32, i1 } { i32 undef, i1 false }, i32 [[RES1]], 0
; CHECK-NEXT: [[SUB:%.*]] = extractvalue { i32, i1 } [[TMP0]], 0
; CHECK-NEXT: br label [[CONT3:%.*]]
@@ -1066,7 +1066,7 @@
; CHECK-NEXT: br i1 [[CMP2]], label [[CONT2:%.*]], label [[OUT]]
; CHECK: cont2:
; CHECK-NEXT: [[OFFSET:%.*]] = add nuw nsw i32 [[X]], 9
-; CHECK-NEXT: [[RES1:%.*]] = sub nuw i32 [[OFFSET]], [[Y]]
+; CHECK-NEXT: [[RES1:%.*]] = sub nuw nsw i32 [[OFFSET]], [[Y]]
; CHECK-NEXT: [[TMP0:%.*]] = insertvalue { i32, i1 } { i32 undef, i1 false }, i32 [[RES1]], 0
; CHECK-NEXT: [[SUB:%.*]] = extractvalue { i32, i1 } [[TMP0]], 0
; CHECK-NEXT: br label [[CONT3:%.*]]
@@ -1155,7 +1155,7 @@
; CHECK-NEXT: [[CMP2:%.*]] = icmp ult i32 [[Y:%.*]], 100
; CHECK-NEXT: br i1 [[CMP2]], label [[CONT2:%.*]], label [[OUT]]
; CHECK: cont2:
-; CHECK-NEXT: [[RES1:%.*]] = mul nuw i32 [[X]], [[Y]]
+; CHECK-NEXT: [[RES1:%.*]] = mul nuw nsw i32 [[X]], [[Y]]
; CHECK-NEXT: [[TMP0:%.*]] = insertvalue { i32, i1 } { i32 undef, i1 false }, i32 [[RES1]], 0
; CHECK-NEXT: [[MUL:%.*]] = extractvalue { i32, i1 } [[TMP0]], 0
; CHECK-NEXT: br label [[CONT3:%.*]]
