[InstCombine] add tests for select to logic folds; NFC

As discussed in D45862, we want these folds sometimes
because they're good improvements.
But as we can see here, the current logic doesn't
check uses and doesn't produce optimal code in all
cases.

llvm-svn: 330837

diff --git a/llvm/test/Transforms/InstCombine/select-icmp-and.ll b/llvm/test/Transforms/InstCombine/select-icmp-and.ll
index ac2b932..7f3f3e4 100644 (file)
--- a/llvm/test/Transforms/InstCombine/select-icmp-and.ll
+++ b/llvm/test/Transforms/InstCombine/select-icmp-and.ll
@@ -442,3 +442,197 @@ define i32 @test15j(i32 %X) {
   ret i32 %t3
 }
 
+declare void @use1(i1)
+
+; (X & 8) == 0 ? -3 : -11 --> (X & 8) ^ -3
+; Extra cmp use ensures that cmp predicate canonicalization is thwarted.
+
+define i32 @clear_to_set(i32 %x) {
+; CHECK-LABEL: @clear_to_set(
+; CHECK-NEXT:    [[T1:%.*]] = and i32 [[X:%.*]], 8
+; CHECK-NEXT:    [[T2:%.*]] = icmp eq i32 [[T1]], 0
+; CHECK-NEXT:    [[TMP1:%.*]] = xor i32 [[T1]], -3
+; CHECK-NEXT:    call void @use1(i1 [[T2]])
+; CHECK-NEXT:    ret i32 [[TMP1]]
+;
+  %t1 = and i32 %x, 8
+  %t2 = icmp eq i32 %t1, 0
+  %t3 = select i1 %t2, i32 -3, i32 -11
+  call void @use1(i1 %t2)
+  ret i32 %t3
+}
+
+; (X & 8) == 0 ? -11 : -3 --> (X & 8) | -11
+; Extra cmp use ensures that cmp predicate canonicalization is thwarted.
+
+define i32 @clear_to_clear(i32 %x) {
+; CHECK-LABEL: @clear_to_clear(
+; CHECK-NEXT:    [[T1:%.*]] = and i32 [[X:%.*]], 8
+; CHECK-NEXT:    [[T2:%.*]] = icmp eq i32 [[T1]], 0
+; CHECK-NEXT:    [[TMP1:%.*]] = or i32 [[T1]], -11
+; CHECK-NEXT:    call void @use1(i1 [[T2]])
+; CHECK-NEXT:    ret i32 [[TMP1]]
+;
+  %t1 = and i32 %x, 8
+  %t2 = icmp eq i32 %t1, 0
+  %t3 = select i1 %t2, i32 -11, i32 -3
+  call void @use1(i1 %t2)
+  ret i32 %t3
+}
+
+; (X & 8) != 0 ? -3 : -11 --> (X & 8) | -11
+; Extra cmp use ensures that cmp predicate canonicalization is thwarted.
+
+define i32 @set_to_set(i32 %x) {
+; CHECK-LABEL: @set_to_set(
+; CHECK-NEXT:    [[T1:%.*]] = and i32 [[X:%.*]], 8
+; CHECK-NEXT:    [[T2:%.*]] = icmp ne i32 [[T1]], 0
+; CHECK-NEXT:    [[TMP1:%.*]] = or i32 [[T1]], -11
+; CHECK-NEXT:    call void @use1(i1 [[T2]])
+; CHECK-NEXT:    ret i32 [[TMP1]]
+;
+  %t1 = and i32 %x, 8
+  %t2 = icmp ne i32 %t1, 0
+  %t3 = select i1 %t2, i32 -3, i32 -11
+  call void @use1(i1 %t2)
+  ret i32 %t3
+}
+
+; (X & 8) != 0 ? -3 : -11 --> (X & 8) ^ -3
+; Extra cmp use ensures that cmp predicate canonicalization is thwarted.
+
+define i32 @set_to_clear(i32 %x) {
+; CHECK-LABEL: @set_to_clear(
+; CHECK-NEXT:    [[T1:%.*]] = and i32 [[X:%.*]], 8
+; CHECK-NEXT:    [[T2:%.*]] = icmp ne i32 [[T1]], 0
+; CHECK-NEXT:    [[TMP1:%.*]] = xor i32 [[T1]], -3
+; CHECK-NEXT:    call void @use1(i1 [[T2]])
+; CHECK-NEXT:    ret i32 [[TMP1]]
+;
+  %t1 = and i32 %x, 8
+  %t2 = icmp ne i32 %t1, 0
+  %t3 = select i1 %t2, i32 -11, i32 -3
+  call void @use1(i1 %t2)
+  ret i32 %t3
+}
+
+; (X & 128) == 0 ? 131 : 3 --> (X & 128) ^ 131
+
+define i8 @clear_to_set_decomposebittest(i8 %x) {
+; CHECK-LABEL: @clear_to_set_decomposebittest(
+; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[X:%.*]], -128
+; CHECK-NEXT:    [[TMP2:%.*]] = add i8 [[TMP1]], -125
+; CHECK-NEXT:    ret i8 [[TMP2]]
+;
+  %t2 = icmp sgt i8 %x, -1
+  %t3 = select i1 %t2, i8 131, i8 3
+  ret i8 %t3
+}
+
+; (X & 128) == 0 ? 3 : 131 --> (X & 128) | 3
+
+define i8 @clear_to_clear_decomposebittest(i8 %x) {
+; CHECK-LABEL: @clear_to_clear_decomposebittest(
+; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[X:%.*]], -128
+; CHECK-NEXT:    [[TMP2:%.*]] = or i8 [[TMP1]], 3
+; CHECK-NEXT:    ret i8 [[TMP2]]
+;
+  %t2 = icmp sgt i8 %x, -1
+  %t3 = select i1 %t2, i8 3, i8 131
+  ret i8 %t3
+}
+
+; (X & 128) != 0 ? 131 : 3 --> (X & 128) | 3
+
+define i8 @set_to_set_decomposebittest(i8 %x) {
+; CHECK-LABEL: @set_to_set_decomposebittest(
+; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[X:%.*]], -128
+; CHECK-NEXT:    [[TMP2:%.*]] = or i8 [[TMP1]], 3
+; CHECK-NEXT:    ret i8 [[TMP2]]
+;
+  %t2 = icmp slt i8 %x, 0
+  %t3 = select i1 %t2, i8 131, i8 3
+  ret i8 %t3
+}
+
+; (X & 128) != 0 ? 3 : 131 --> (X & 128) ^ 131
+
+define i8 @set_to_clear_decomposebittest(i8 %x) {
+; CHECK-LABEL: @set_to_clear_decomposebittest(
+; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[X:%.*]], -128
+; CHECK-NEXT:    [[TMP2:%.*]] = add i8 [[TMP1]], -125
+; CHECK-NEXT:    ret i8 [[TMP2]]
+;
+  %t2 = icmp slt i8 %x, 0
+  %t3 = select i1 %t2, i8 3, i8 131
+  ret i8 %t3
+}
+
+; (X & 128) == 0 ? 131 : 3 --> (X & 128) ^ 131
+; Extra cmp use to verify that we are not creating extra instructions.
+
+define i8 @clear_to_set_decomposebittest_extra_use(i8 %x) {
+; CHECK-LABEL: @clear_to_set_decomposebittest_extra_use(
+; CHECK-NEXT:    [[T2:%.*]] = icmp sgt i8 [[X:%.*]], -1
+; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[X]], -128
+; CHECK-NEXT:    [[TMP2:%.*]] = add i8 [[TMP1]], -125
+; CHECK-NEXT:    call void @use1(i1 [[T2]])
+; CHECK-NEXT:    ret i8 [[TMP2]]
+;
+  %t2 = icmp sgt i8 %x, -1
+  %t3 = select i1 %t2, i8 131, i8 3
+  call void @use1(i1 %t2)
+  ret i8 %t3
+}
+
+; (X & 128) == 0 ? 3 : 131 --> (X & 128) | 3
+; Extra cmp use to verify that we are not creating extra instructions.
+
+define i8 @clear_to_clear_decomposebittest_extra_use(i8 %x) {
+; CHECK-LABEL: @clear_to_clear_decomposebittest_extra_use(
+; CHECK-NEXT:    [[T2:%.*]] = icmp sgt i8 [[X:%.*]], -1
+; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[X]], -128
+; CHECK-NEXT:    [[TMP2:%.*]] = or i8 [[TMP1]], 3
+; CHECK-NEXT:    call void @use1(i1 [[T2]])
+; CHECK-NEXT:    ret i8 [[TMP2]]
+;
+  %t2 = icmp sgt i8 %x, -1
+  %t3 = select i1 %t2, i8 3, i8 131
+  call void @use1(i1 %t2)
+  ret i8 %t3
+}
+
+; (X & 128) != 0 ? 131 : 3 --> (X & 128) | 3
+; Extra cmp use to verify that we are not creating extra instructions.
+
+define i8 @set_to_set_decomposebittest_extra_use(i8 %x) {
+; CHECK-LABEL: @set_to_set_decomposebittest_extra_use(
+; CHECK-NEXT:    [[T2:%.*]] = icmp slt i8 [[X:%.*]], 0
+; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[X]], -128
+; CHECK-NEXT:    [[TMP2:%.*]] = or i8 [[TMP1]], 3
+; CHECK-NEXT:    call void @use1(i1 [[T2]])
+; CHECK-NEXT:    ret i8 [[TMP2]]
+;
+  %t2 = icmp slt i8 %x, 0
+  %t3 = select i1 %t2, i8 131, i8 3
+  call void @use1(i1 %t2)
+  ret i8 %t3
+}
+
+; (X & 128) != 0 ? 3 : 131 --> (X & 128) ^ 131
+; Extra cmp use to verify that we are not creating extra instructions.
+
+define i8 @set_to_clear_decomposebittest_extra_use(i8 %x) {
+; CHECK-LABEL: @set_to_clear_decomposebittest_extra_use(
+; CHECK-NEXT:    [[T2:%.*]] = icmp slt i8 [[X:%.*]], 0
+; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[X]], -128
+; CHECK-NEXT:    [[TMP2:%.*]] = add i8 [[TMP1]], -125
+; CHECK-NEXT:    call void @use1(i1 [[T2]])
+; CHECK-NEXT:    ret i8 [[TMP2]]
+;
+  %t2 = icmp slt i8 %x, 0
+  %t3 = select i1 %t2, i8 3, i8 131
+  call void @use1(i1 %t2)
+  ret i8 %t3
+}
+