[Instcombine] Test for more gep canonicalization

Author: davemgreen

llvm/test/Transforms/InstCombine/canonicalize-gep-constglob.ll

@@ -0,0 +1,60 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
+; RUN: opt < %s -passes=instcombine -S | FileCheck %s
+
+@glob = internal global [10 x [10 x [10 x i32]]] zeroinitializer
+
+define ptr @x12(i64 %x) {
+; CHECK-LABEL: define ptr @x12(
+; CHECK-SAME: i64 [[X:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[GEP:%.*]] = getelementptr inbounds [10 x [10 x [10 x i32]]], ptr getelementptr inbounds (i8, ptr @glob, i64 36), i64 0, i64 [[X]], i64 1, i64 2
+; CHECK-NEXT:    ret ptr [[GEP]]
+;
+entry:
+  %gep = getelementptr inbounds [10 x [10 x [10 x i32]]], ptr getelementptr (i8, ptr @glob, i64 36), i64 0, i64 %x, i64 1, i64 2
+  ret ptr %gep
+}
+
+define ptr @x1y(i64 %x, i64 %y) {
+; CHECK-LABEL: define ptr @x1y(
+; CHECK-SAME: i64 [[X:%.*]], i64 [[Y:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[GEP:%.*]] = getelementptr inbounds [10 x [10 x [10 x i32]]], ptr getelementptr inbounds (i8, ptr @glob, i64 36), i64 0, i64 [[X]], i64 2, i64 [[Y]]
+; CHECK-NEXT:    ret ptr [[GEP]]
+;
+entry:
+  %gep = getelementptr inbounds [10 x [10 x [10 x i32]]], ptr getelementptr (i8, ptr @glob, i64 36), i64 0, i64 %x, i64 2, i64 %y
+  ret ptr %gep
+}
+
+define ptr @xzy(i64 %x, i64 %y, i64 %z) {
+; CHECK-LABEL: define ptr @xzy(
+; CHECK-SAME: i64 [[X:%.*]], i64 [[Y:%.*]], i64 [[Z:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[GEP:%.*]] = getelementptr inbounds [10 x [10 x [10 x i32]]], ptr getelementptr inbounds (i8, ptr @glob, i64 40), i64 0, i64 [[X]], i64 [[Z]], i64 [[Y]]
+; CHECK-NEXT:    ret ptr [[GEP]]
+;
+entry:
+  %gep = getelementptr inbounds [10 x [10 x [10 x i32]]], ptr getelementptr (i8, ptr @glob, i64 40), i64 0, i64 %x, i64 %z, i64 %y
+  ret ptr %gep
+}
+
+define i32 @twoloads(i64 %x) {
+; CHECK-LABEL: define i32 @twoloads(
+; CHECK-SAME: i64 [[X:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[GEP1:%.*]] = getelementptr inbounds [10 x [10 x [10 x i32]]], ptr getelementptr inbounds (i8, ptr @glob, i64 50), i64 0, i64 [[X]], i64 2, i64 1
+; CHECK-NEXT:    [[GEP2:%.*]] = getelementptr inbounds [10 x [10 x [10 x i32]]], ptr getelementptr inbounds (i8, ptr @glob, i64 36), i64 0, i64 [[X]], i64 2, i64 4
+; CHECK-NEXT:    [[A:%.*]] = load i32, ptr [[GEP1]], align 4
+; CHECK-NEXT:    [[B:%.*]] = load i32, ptr [[GEP2]], align 4
+; CHECK-NEXT:    [[C:%.*]] = add i32 [[A]], [[B]]
+; CHECK-NEXT:    ret i32 [[C]]
+;
+entry:
+  %gep1 = getelementptr inbounds [10 x [10 x [10 x i32]]], ptr getelementptr (i8, ptr @glob, i64 50), i64 0, i64 %x, i64 2, i64 1
+  %gep2 = getelementptr inbounds [10 x [10 x [10 x i32]]], ptr getelementptr (i8, ptr @glob, i64 36), i64 0, i64 %x, i64 2, i64 4
+  %a = load i32, ptr %gep1
+  %b = load i32, ptr %gep2
+  %c = add i32 %a, %b
+  ret i32 %c
+}