[InstCombine] Add more inbounds tests for indexed compare fold (NFC)

Don't only test the case where all GEPs are missing inbounds, also
test inbounds only being present on some of them. The fold should
not be performed in either case.

Author: nikic

llvm/test/Transforms/InstCombine/indexed-gep-compares.ll

@@ -64,15 +64,15 @@ bb2:
 }
 
 ; Perform the transformation only if we know that the GEPs used are inbounds.
-define ptr@test3(ptr %A, i32 %Offset) {
-; CHECK-LABEL: @test3(
+define ptr @test3_no_inbounds1(ptr %A, i32 %Offset) {
+; CHECK-LABEL: @test3_no_inbounds1(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP:%.*]] = getelementptr i32, ptr [[A:%.*]], i32 [[OFFSET:%.*]]
 ; CHECK-NEXT:    br label [[BB:%.*]]
 ; CHECK:       bb:
 ; CHECK-NEXT:    [[RHS:%.*]] = phi ptr [ [[RHS_NEXT:%.*]], [[BB]] ], [ [[TMP]], [[ENTRY:%.*]] ]
-; CHECK-NEXT:    [[LHS:%.*]] = getelementptr i32, ptr [[A]], i32 100
-; CHECK-NEXT:    [[RHS_NEXT]] = getelementptr i32, ptr [[RHS]], i32 1
+; CHECK-NEXT:    [[LHS:%.*]] = getelementptr inbounds i32, ptr [[A]], i32 100
+; CHECK-NEXT:    [[RHS_NEXT]] = getelementptr inbounds i32, ptr [[RHS]], i32 1
 ; CHECK-NEXT:    [[COND:%.*]] = icmp ult ptr [[LHS]], [[RHS]]
 ; CHECK-NEXT:    br i1 [[COND]], label [[BB2:%.*]], label [[BB]]
 ; CHECK:       bb2:
@@ -84,7 +84,36 @@ entry:
 
 bb:
   %RHS = phi ptr [ %RHS.next, %bb ], [ %tmp, %entry ]
-  %LHS = getelementptr i32, ptr %A, i32 100
+  %LHS = getelementptr inbounds i32, ptr %A, i32 100
+  %RHS.next = getelementptr inbounds i32, ptr %RHS, i64 1
+  %cond = icmp ult ptr %LHS, %RHS
+  br i1 %cond, label %bb2, label %bb
+
+bb2:
+  ret ptr %RHS
+}
+
+define ptr @test3_no_inbounds2(ptr %A, i32 %Offset) {
+; CHECK-LABEL: @test3_no_inbounds2(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP:%.*]] = getelementptr inbounds i32, ptr [[A:%.*]], i32 [[OFFSET:%.*]]
+; CHECK-NEXT:    br label [[BB:%.*]]
+; CHECK:       bb:
+; CHECK-NEXT:    [[RHS:%.*]] = phi ptr [ [[RHS_NEXT:%.*]], [[BB]] ], [ [[TMP]], [[ENTRY:%.*]] ]
+; CHECK-NEXT:    [[LHS:%.*]] = getelementptr inbounds i32, ptr [[A]], i32 100
+; CHECK-NEXT:    [[RHS_NEXT]] = getelementptr i32, ptr [[RHS]], i32 1
+; CHECK-NEXT:    [[COND:%.*]] = icmp ult ptr [[LHS]], [[RHS]]
+; CHECK-NEXT:    br i1 [[COND]], label [[BB2:%.*]], label [[BB]]
+; CHECK:       bb2:
+; CHECK-NEXT:    ret ptr [[RHS]]
+;
+entry:
+  %tmp = getelementptr inbounds i32, ptr %A, i32 %Offset
+  br label %bb
+
+bb:
+  %RHS = phi ptr [ %RHS.next, %bb ], [ %tmp, %entry ]
+  %LHS = getelementptr inbounds i32, ptr %A, i32 100
   %RHS.next = getelementptr i32, ptr %RHS, i64 1
   %cond = icmp ult ptr %LHS, %RHS
   br i1 %cond, label %bb2, label %bb
@@ -93,6 +122,35 @@ bb2:
   ret ptr %RHS
 }
 
+define ptr @test3_no_inbounds3(ptr %A, i32 %Offset) {
+; CHECK-LABEL: @test3_no_inbounds3(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP:%.*]] = getelementptr inbounds i32, ptr [[A:%.*]], i32 [[OFFSET:%.*]]
+; CHECK-NEXT:    br label [[BB:%.*]]
+; CHECK:       bb:
+; CHECK-NEXT:    [[RHS:%.*]] = phi ptr [ [[RHS_NEXT:%.*]], [[BB]] ], [ [[TMP]], [[ENTRY:%.*]] ]
+; CHECK-NEXT:    [[LHS:%.*]] = getelementptr i32, ptr [[A]], i32 100
+; CHECK-NEXT:    [[RHS_NEXT]] = getelementptr inbounds i32, ptr [[RHS]], i32 1
+; CHECK-NEXT:    [[COND:%.*]] = icmp ult ptr [[LHS]], [[RHS]]
+; CHECK-NEXT:    br i1 [[COND]], label [[BB2:%.*]], label [[BB]]
+; CHECK:       bb2:
+; CHECK-NEXT:    ret ptr [[RHS]]
+;
+entry:
+  %tmp = getelementptr inbounds i32, ptr %A, i32 %Offset
+  br label %bb
+
+bb:
+  %RHS = phi ptr [ %RHS.next, %bb ], [ %tmp, %entry ]
+  %LHS = getelementptr i32, ptr %A, i32 100
+  %RHS.next = getelementptr inbounds i32, ptr %RHS, i64 1
+  %cond = icmp ult ptr %LHS, %RHS
+  br i1 %cond, label %bb2, label %bb
+
+bb2:
+  ret ptr %RHS
+}
+
 ; An inttoptr that requires an extension or truncation will be opaque when determining
 ; the base pointer. In this case we can still perform the transformation by considering
 ; A.ptr as being the base pointer.