[InstCombine] add baseline tests for D39958; NFC

llvm-svn: 322733

1 files changed, 143 insertions, 0 deletions

diff --git a/llvm/test/Transforms/InstCombine/select-gep.ll b/llvm/test/Transforms/InstCombine/select-gep.ll
new file mode 100644
index 00000000000..41304a8de0b
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/select-gep.ll
@@ -0,0 +1,143 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+define i32* @test1a(i32* %p, i32* %q) {
+; CHECK-LABEL: @test1a(
+; CHECK-NEXT:    [[GEP1:%.*]] = getelementptr i32, i32* [[P:%.*]], i64 4
+; CHECK-NEXT:    [[GEP2:%.*]] = getelementptr i32, i32* [[Q:%.*]], i64 4
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i32* [[P]], [[Q]]
+; CHECK-NEXT:    [[SELECT:%.*]] = select i1 [[CMP]], i32* [[GEP1]], i32* [[GEP2]]
+; CHECK-NEXT:    ret i32* [[SELECT]]
+;
+  %gep1 = getelementptr i32, i32* %p, i64 4
+  %gep2 = getelementptr i32, i32* %q, i64 4
+  %cmp = icmp ugt i32* %p, %q
+  %select = select i1 %cmp, i32* %gep1, i32* %gep2
+  ret i32* %select
+}
+
+define i32* @test1b(i32* %p, i32* %q) {
+; CHECK-LABEL: @test1b(
+; CHECK-NEXT:    [[GEP1:%.*]] = getelementptr inbounds i32, i32* [[P:%.*]], i64 4
+; CHECK-NEXT:    [[GEP2:%.*]] = getelementptr i32, i32* [[Q:%.*]], i64 4
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i32* [[P]], [[Q]]
+; CHECK-NEXT:    [[SELECT:%.*]] = select i1 [[CMP]], i32* [[GEP1]], i32* [[GEP2]]
+; CHECK-NEXT:    ret i32* [[SELECT]]
+;
+  %gep1 = getelementptr inbounds i32, i32* %p, i64 4
+  %gep2 = getelementptr i32, i32* %q, i64 4
+  %cmp = icmp ugt i32* %p, %q
+  %select = select i1 %cmp, i32* %gep1, i32* %gep2
+  ret i32* %select
+}
+
+define i32* @test1c(i32* %p, i32* %q) {
+; CHECK-LABEL: @test1c(
+; CHECK-NEXT:    [[GEP1:%.*]] = getelementptr i32, i32* [[P:%.*]], i64 4
+; CHECK-NEXT:    [[GEP2:%.*]] = getelementptr inbounds i32, i32* [[Q:%.*]], i64 4
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i32* [[P]], [[Q]]
+; CHECK-NEXT:    [[SELECT:%.*]] = select i1 [[CMP]], i32* [[GEP1]], i32* [[GEP2]]
+; CHECK-NEXT:    ret i32* [[SELECT]]
+;
+  %gep1 = getelementptr i32, i32* %p, i64 4
+  %gep2 = getelementptr inbounds i32, i32* %q, i64 4
+  %cmp = icmp ugt i32* %p, %q
+  %select = select i1 %cmp, i32* %gep1, i32* %gep2
+  ret i32* %select
+}
+
+define i32* @test1d(i32* %p, i32* %q) {
+; CHECK-LABEL: @test1d(
+; CHECK-NEXT:    [[GEP1:%.*]] = getelementptr inbounds i32, i32* [[P:%.*]], i64 4
+; CHECK-NEXT:    [[GEP2:%.*]] = getelementptr inbounds i32, i32* [[Q:%.*]], i64 4
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i32* [[P]], [[Q]]
+; CHECK-NEXT:    [[SELECT:%.*]] = select i1 [[CMP]], i32* [[GEP1]], i32* [[GEP2]]
+; CHECK-NEXT:    ret i32* [[SELECT]]
+;
+  %gep1 = getelementptr inbounds i32, i32* %p, i64 4
+  %gep2 = getelementptr inbounds i32, i32* %q, i64 4
+  %cmp = icmp ugt i32* %p, %q
+  %select = select i1 %cmp, i32* %gep1, i32* %gep2
+  ret i32* %select
+}
+
+define i32* @test2(i32* %p, i64 %x, i64 %y) {
+; CHECK-LABEL: @test2(
+; CHECK-NEXT:    [[GEP1:%.*]] = getelementptr inbounds i32, i32* [[P:%.*]], i64 [[X:%.*]]
+; CHECK-NEXT:    [[GEP2:%.*]] = getelementptr inbounds i32, i32* [[P]], i64 [[Y:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i64 [[X]], [[Y]]
+; CHECK-NEXT:    [[SELECT:%.*]] = select i1 [[CMP]], i32* [[GEP1]], i32* [[GEP2]]
+; CHECK-NEXT:    ret i32* [[SELECT]]
+;
+  %gep1 = getelementptr inbounds i32, i32* %p, i64 %x
+  %gep2 = getelementptr inbounds i32, i32* %p, i64 %y
+  %cmp = icmp ugt i64 %x, %y
+  %select = select i1 %cmp, i32* %gep1, i32* %gep2
+  ret i32* %select
+}
+
+; Three (or more) operand GEPs are currently expected to not be optimised,
+; though they could be in principle.
+
+define i32* @test3a([4 x i32]* %p, i64 %x, i64 %y) {
+; CHECK-LABEL: @test3a(
+; CHECK-NEXT:    [[GEP1:%.*]] = getelementptr inbounds [4 x i32], [4 x i32]* [[P:%.*]], i64 2, i64 [[X:%.*]]
+; CHECK-NEXT:    [[GEP2:%.*]] = getelementptr inbounds [4 x i32], [4 x i32]* [[P]], i64 2, i64 [[Y:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i64 [[X]], [[Y]]
+; CHECK-NEXT:    [[SELECT:%.*]] = select i1 [[CMP]], i32* [[GEP1]], i32* [[GEP2]]
+; CHECK-NEXT:    ret i32* [[SELECT]]
+;
+  %gep1 = getelementptr inbounds [4 x i32], [4 x i32]* %p, i64 2, i64 %x
+  %gep2 = getelementptr inbounds [4 x i32], [4 x i32]* %p, i64 2, i64 %y
+  %cmp = icmp ugt i64 %x, %y
+  %select = select i1 %cmp, i32* %gep1, i32* %gep2
+  ret i32* %select
+}
+
+define i32* @test3b([4 x i32]* %p, i32* %q, i64 %x, i64 %y) {
+; CHECK-LABEL: @test3b(
+; CHECK-NEXT:    [[GEP1:%.*]] = getelementptr inbounds [4 x i32], [4 x i32]* [[P:%.*]], i64 [[X:%.*]], i64 2
+; CHECK-NEXT:    [[GEP2:%.*]] = getelementptr inbounds i32, i32* [[Q:%.*]], i64 [[X]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i64 [[X]], [[Y:%.*]]
+; CHECK-NEXT:    [[SELECT:%.*]] = select i1 [[CMP]], i32* [[GEP1]], i32* [[GEP2]]
+; CHECK-NEXT:    ret i32* [[SELECT]]
+;
+  %gep1 = getelementptr inbounds [4 x i32], [4 x i32]* %p, i64 %x, i64 2
+  %gep2 = getelementptr inbounds i32, i32* %q, i64 %x
+  %cmp = icmp ugt i64 %x, %y
+  %select = select i1 %cmp, i32* %gep1, i32* %gep2
+  ret i32* %select
+}
+
+define i32* @test3c(i32* %p, [4 x i32]* %q, i64 %x, i64 %y) {
+; CHECK-LABEL: @test3c(
+; CHECK-NEXT:    [[GEP1:%.*]] = getelementptr inbounds i32, i32* [[P:%.*]], i64 [[X:%.*]]
+; CHECK-NEXT:    [[GEP2:%.*]] = getelementptr inbounds [4 x i32], [4 x i32]* [[Q:%.*]], i64 [[X]], i64 2
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i64 [[X]], [[Y:%.*]]
+; CHECK-NEXT:    [[SELECT:%.*]] = select i1 [[CMP]], i32* [[GEP1]], i32* [[GEP2]]
+; CHECK-NEXT:    ret i32* [[SELECT]]
+;
+  %gep1 = getelementptr inbounds i32, i32* %p, i64 %x
+  %gep2 = getelementptr inbounds [4 x i32], [4 x i32]* %q, i64 %x, i64 2
+  %cmp = icmp ugt i64 %x, %y
+  %select = select i1 %cmp, i32* %gep1, i32* %gep2
+  ret i32* %select
+}
+
+; Shouldn't be optimised as it would mean introducing an extra select
+
+define i32* @test4(i32* %p, i32* %q, i64 %x, i64 %y) {
+; CHECK-LABEL: @test4(
+; CHECK-NEXT:    [[GEP1:%.*]] = getelementptr inbounds i32, i32* [[P:%.*]], i64 [[X:%.*]]
+; CHECK-NEXT:    [[GEP2:%.*]] = getelementptr inbounds i32, i32* [[Q:%.*]], i64 [[Y:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i64 [[X]], [[Y]]
+; CHECK-NEXT:    [[SELECT:%.*]] = select i1 [[CMP]], i32* [[GEP1]], i32* [[GEP2]]
+; CHECK-NEXT:    ret i32* [[SELECT]]
+;
+  %gep1 = getelementptr inbounds i32, i32* %p, i64 %x
+  %gep2 = getelementptr inbounds i32, i32* %q, i64 %y
+  %cmp = icmp ugt i64 %x, %y
+  %select = select i1 %cmp, i32* %gep1, i32* %gep2
+  ret i32* %select
+}
+