[llvm] 853c52c - [ConstraintElimination] Require GEPs to be inbounds for decomposition.

[Florian Hahn via llvm-commits]

Author: Florian Hahn
Date: 2021-02-07T11:08:53Z
New Revision: 853c52c988d4ef56b0f7e02819d1976262b6ab0a

URL: https://github.com/llvm/llvm-project/commit/853c52c988d4ef56b0f7e02819d1976262b6ab0a
DIFF: https://github.com/llvm/llvm-project/commit/853c52c988d4ef56b0f7e02819d1976262b6ab0a.diff

LOG: [ConstraintElimination] Require GEPs to be inbounds for decomposition.

During decomposition, we assume the no-wrap properties of inbound GEPs.
Make sure the decomposed GEP is actually inbounds.

Added: 
    

Modified: 
    llvm/lib/Transforms/Scalar/ConstraintElimination.cpp
    llvm/test/Transforms/ConstraintElimination/gep-arithmetic.ll
    llvm/test/Transforms/ConstraintElimination/geps.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp b/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp
index f6a6b4807adf..50e9d5fbd9ff 100644
--- a/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp
+++ b/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp
@@ -53,7 +53,7 @@ static SmallVector<std::pair<int64_t, Value *>, 4> decompose(Value *V) {
     return {{CI->getSExtValue(), nullptr}};
   }
   auto *GEP = dyn_cast<GetElementPtrInst>(V);
-  if (GEP && GEP->getNumOperands() == 2) {
+  if (GEP && GEP->getNumOperands() == 2 && GEP->isInBounds()) {
     if (isa<ConstantInt>(GEP->getOperand(GEP->getNumOperands() - 1))) {
       return {{cast<ConstantInt>(GEP->getOperand(GEP->getNumOperands() - 1))
                    ->getSExtValue(),

diff  --git a/llvm/test/Transforms/ConstraintElimination/gep-arithmetic.ll b/llvm/test/Transforms/ConstraintElimination/gep-arithmetic.ll
index 08af75a71dc9..5e1f688440cb 100644
--- a/llvm/test/Transforms/ConstraintElimination/gep-arithmetic.ll
+++ b/llvm/test/Transforms/ConstraintElimination/gep-arithmetic.ll
@@ -151,7 +151,7 @@ define i4 @ptr_N_signed_positive_explicit_check_constant_step_no_inbonds(i8* %sr
 ; CHECK-NEXT:    [[SRC_STEP:%.*]] = getelementptr i8, i8* [[SRC]], i16 1
 ; CHECK-NEXT:    [[CMP_STEP_START:%.*]] = icmp ult i8* [[SRC_STEP]], [[LOWER]]
 ; CHECK-NEXT:    [[CMP_STEP_END:%.*]] = icmp uge i8* [[SRC_STEP]], [[UPPER]]
-; CHECK-NEXT:    [[OR_CHECK:%.*]] = or i1 false, false
+; CHECK-NEXT:    [[OR_CHECK:%.*]] = or i1 [[CMP_STEP_START]], [[CMP_STEP_END]]
 ; CHECK-NEXT:    br i1 [[OR_CHECK]], label [[TRAP_BB]], label [[EXIT]]
 ; CHECK:       exit:
 ; CHECK-NEXT:    ret i4 3

diff  --git a/llvm/test/Transforms/ConstraintElimination/geps.ll b/llvm/test/Transforms/ConstraintElimination/geps.ll
index 0693a5c5c8e7..5c891f3c3909 100644
--- a/llvm/test/Transforms/ConstraintElimination/geps.ll
+++ b/llvm/test/Transforms/ConstraintElimination/geps.ll
@@ -106,7 +106,7 @@ define i32 @test.ult_no_inbounds(i32* readonly %src, i32* readnone %min, i32* re
 ; CHECK-NEXT:    [[L0:%.*]] = load i32, i32* [[SRC]], align 4
 ; CHECK-NEXT:    [[ADD_PTR_I36:%.*]] = getelementptr i32, i32* [[SRC]], i64 3
 ; CHECK-NEXT:    [[C_3_MIN:%.*]] = icmp ult i32* [[ADD_PTR_I36]], [[MIN]]
-; CHECK-NEXT:    br i1 false, label [[TRAP]], label [[CHECK_3_MAX:%.*]]
+; CHECK-NEXT:    br i1 [[C_3_MIN]], label [[TRAP]], label [[CHECK_3_MAX:%.*]]
 ; CHECK:       check.3.max:
 ; CHECK-NEXT:    [[C_3_MAX:%.*]] = icmp ult i32* [[ADD_PTR_I36]], [[MAX]]
 ; CHECK-NEXT:    br i1 [[C_3_MAX]], label [[CHECK_1_MIN:%.*]], label [[TRAP]]
@@ -114,18 +114,18 @@ define i32 @test.ult_no_inbounds(i32* readonly %src, i32* readnone %min, i32* re
 ; CHECK-NEXT:    [[L1:%.*]] = load i32, i32* [[ADD_PTR_I36]], align 4
 ; CHECK-NEXT:    [[ADD_PTR_I29:%.*]] = getelementptr i32, i32* [[SRC]], i64 1
 ; CHECK-NEXT:    [[C_1_MIN:%.*]] = icmp ult i32* [[ADD_PTR_I29]], [[MIN]]
-; CHECK-NEXT:    br i1 false, label [[TRAP]], label [[CHECK_1_MAX:%.*]]
+; CHECK-NEXT:    br i1 [[C_1_MIN]], label [[TRAP]], label [[CHECK_1_MAX:%.*]]
 ; CHECK:       check.1.max:
 ; CHECK-NEXT:    [[C_1_MAX:%.*]] = icmp ult i32* [[ADD_PTR_I29]], [[MAX]]
-; CHECK-NEXT:    br i1 true, label [[CHECK_2_MIN:%.*]], label [[TRAP]]
+; CHECK-NEXT:    br i1 [[C_1_MAX]], label [[CHECK_2_MIN:%.*]], label [[TRAP]]
 ; CHECK:       check.2.min:
 ; CHECK-NEXT:    [[L2:%.*]] = load i32, i32* [[ADD_PTR_I29]], align 4
 ; CHECK-NEXT:    [[ADD_PTR_I:%.*]] = getelementptr i32, i32* [[SRC]], i64 2
 ; CHECK-NEXT:    [[C_2_MIN:%.*]] = icmp ult i32* [[ADD_PTR_I]], [[MIN]]
-; CHECK-NEXT:    br i1 false, label [[TRAP]], label [[CHECK_2_MAX:%.*]]
+; CHECK-NEXT:    br i1 [[C_2_MIN]], label [[TRAP]], label [[CHECK_2_MAX:%.*]]
 ; CHECK:       check.2.max:
 ; CHECK-NEXT:    [[C_2_MAX:%.*]] = icmp ult i32* [[ADD_PTR_I]], [[MAX]]
-; CHECK-NEXT:    br i1 true, label [[EXIT:%.*]], label [[TRAP]]
+; CHECK-NEXT:    br i1 [[C_2_MAX]], label [[EXIT:%.*]], label [[TRAP]]
 ; CHECK:       exit:
 ; CHECK-NEXT:    [[L3:%.*]] = load i32, i32* [[ADD_PTR_I]], align 4
 ; CHECK-NEXT:    [[ADD:%.*]] = add nsw i32 [[L1]], [[L0]]
@@ -245,16 +245,16 @@ define void @test.not.uge.ult_no_inbounds(i8* %start, i8* %low, i8* %high) {
 ; CHECK-NEXT:    ret void
 ; CHECK:       if.end:
 ; CHECK-NEXT:    [[T_0:%.*]] = icmp ult i8* [[START]], [[HIGH]]
-; CHECK-NEXT:    call void @use(i1 true)
+; CHECK-NEXT:    call void @use(i1 [[T_0]])
 ; CHECK-NEXT:    [[START_1:%.*]] = getelementptr i8, i8* [[START]], i64 1
 ; CHECK-NEXT:    [[T_1:%.*]] = icmp ult i8* [[START_1]], [[HIGH]]
-; CHECK-NEXT:    call void @use(i1 true)
+; CHECK-NEXT:    call void @use(i1 [[T_1]])
 ; CHECK-NEXT:    [[START_2:%.*]] = getelementptr i8, i8* [[START]], i64 2
 ; CHECK-NEXT:    [[T_2:%.*]] = icmp ult i8* [[START_2]], [[HIGH]]
-; CHECK-NEXT:    call void @use(i1 true)
+; CHECK-NEXT:    call void @use(i1 [[T_2]])
 ; CHECK-NEXT:    [[START_3:%.*]] = getelementptr i8, i8* [[START]], i64 3
 ; CHECK-NEXT:    [[T_3:%.*]] = icmp ult i8* [[START_3]], [[HIGH]]
-; CHECK-NEXT:    call void @use(i1 true)
+; CHECK-NEXT:    call void @use(i1 [[T_3]])
 ; CHECK-NEXT:    [[START_4:%.*]] = getelementptr i8, i8* [[START]], i64 4
 ; CHECK-NEXT:    [[C_4:%.*]] = icmp ult i8* [[START_4]], [[HIGH]]
 ; CHECK-NEXT:    call void @use(i1 [[C_4]])