[ConstraintElim] Add tests with GEP constant expressions.

Author: fhahn

llvm/test/Transforms/ConstraintElimination/gep-constexpr.ll

@@ -0,0 +1,44 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -passes=constraint-elimination -S %s | FileCheck %s
+
+declare void @llvm.assume(i1 noundef) #0
+
+@arr1 = common global [3 x i16] zeroinitializer, align 2
+
+define i1 @gep_constexpr_index_lt_upper(i32 noundef %i) {
+; CHECK-LABEL: @gep_constexpr_index_lt_upper(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i32 [[I:%.*]], 3
+; CHECK-NEXT:    call void @llvm.assume(i1 [[CMP]])
+; CHECK-NEXT:    [[IDXPROM:%.*]] = zext i32 [[I]] to i64
+; CHECK-NEXT:    [[UPPER:%.*]] = getelementptr inbounds i16, ptr @arr1, i64 [[IDXPROM]]
+; CHECK-NEXT:    [[C_1:%.*]] = icmp ult ptr [[UPPER]], getelementptr inbounds ([3 x i16], ptr @arr1, i64 1, i64 0)
+; CHECK-NEXT:    ret i1 [[C_1]]
+;
+entry:
+  %cmp = icmp ult i32 %i, 3
+  call void @llvm.assume(i1 %cmp)
+  %idxprom = zext i32 %i to i64
+  %upper = getelementptr inbounds i16, ptr @arr1, i64 %idxprom
+  %c.1 = icmp ult ptr %upper, getelementptr inbounds ([3 x i16], ptr @arr1, i64 1, i64 0)
+  ret i1 %c.1
+}
+
+define i1 @gep_constexpr_index_may_be_gt_upper(i32 noundef %i) {
+; CHECK-LABEL: @gep_constexpr_index_may_be_gt_upper(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i32 [[I:%.*]], 3
+; CHECK-NEXT:    call void @llvm.assume(i1 [[CMP]])
+; CHECK-NEXT:    [[IDXPROM:%.*]] = zext i32 [[I]] to i64
+; CHECK-NEXT:    [[UPPER:%.*]] = getelementptr inbounds i16, ptr @arr1, i64 [[IDXPROM]]
+; CHECK-NEXT:    [[C_1:%.*]] = icmp ult ptr [[UPPER]], getelementptr inbounds ([3 x i16], ptr @arr1, i64 0, i64 2)
+; CHECK-NEXT:    ret i1 [[C_1]]
+;
+entry:
+  %cmp = icmp ult i32 %i, 3
+  call void @llvm.assume(i1 %cmp)
+  %idxprom = zext i32 %i to i64
+  %upper = getelementptr inbounds i16, ptr @arr1, i64 %idxprom
+  %c.1 = icmp ult ptr %upper, getelementptr inbounds ([3 x i16], ptr @arr1, i64 0, i64 2)
+  ret i1 %c.1
+}