[InstCombine] add tests for (pow2 >> X) >u C; NFC

diff --git a/llvm/test/Transforms/InstCombine/icmp-shr.ll b/llvm/test/Transforms/InstCombine/icmp-shr.ll
index a6dcf13..2d78916 100644 (file)
--- a/llvm/test/Transforms/InstCombine/icmp-shr.ll
+++ b/llvm/test/Transforms/InstCombine/icmp-shr.ll
@@ -1006,4 +1006,83 @@ define i1 @ashr_exact_ne_0_multiuse(i8 %x) {
   ret i1 %c
 }
 
+define i1 @lshr_pow2_ugt(i8 %x) {
+; CHECK-LABEL: @lshr_pow2_ugt(
+; CHECK-NEXT:    [[S:%.*]] = lshr i8 2, [[X:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp ugt i8 [[S]], 1
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %s = lshr i8 2, %x
+  %r = icmp ugt i8 %s, 1
+  ret i1 %r
+}
+
+define i1 @lshr_pow2_ugt_use(i8 %x) {
+; CHECK-LABEL: @lshr_pow2_ugt_use(
+; CHECK-NEXT:    [[S:%.*]] = lshr i8 -128, [[X:%.*]]
+; CHECK-NEXT:    call void @use(i8 [[S]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ugt i8 [[S]], 5
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %s = lshr i8 128, %x
+  call void @use(i8 %s)
+  %r = icmp ugt i8 %s, 5
+  ret i1 %r
+}
+
+define <2 x i1> @lshr_pow2_ugt_vec(<2 x i8> %x) {
+; CHECK-LABEL: @lshr_pow2_ugt_vec(
+; CHECK-NEXT:    [[S:%.*]] = lshr <2 x i8> <i8 8, i8 8>, [[X:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp ugt <2 x i8> [[S]], <i8 6, i8 6>
+; CHECK-NEXT:    ret <2 x i1> [[R]]
+;
+  %s = lshr <2 x i8> <i8 8, i8 8>, %x
+  %r = icmp ugt <2 x i8> %s, <i8 6, i8 6>
+  ret <2 x i1> %r
+}
+
+define i1 @lshr_not_pow2_ugt(i8 %x) {
+; CHECK-LABEL: @lshr_not_pow2_ugt(
+; CHECK-NEXT:    [[S:%.*]] = lshr i8 3, [[X:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp ugt i8 [[S]], 1
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %s = lshr i8 3, %x
+  %r = icmp ugt i8 %s, 1
+  ret i1 %r
+}
+
+define i1 @lshr_pow2_ugt1(i8 %x) {
+; CHECK-LABEL: @lshr_pow2_ugt1(
+; CHECK-NEXT:    [[S:%.*]] = lshr i8 -128, [[X:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp ugt i8 [[S]], 1
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %s = lshr i8 128, %x
+  %r = icmp ugt i8 %s, 1
+  ret i1 %r
+}
+
+define i1 @ashr_pow2_ugt(i8 %x) {
+; CHECK-LABEL: @ashr_pow2_ugt(
+; CHECK-NEXT:    [[S:%.*]] = ashr i8 -128, [[X:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp ugt i8 [[S]], -96
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %s = ashr i8 128, %x
+  %r = icmp ugt i8 %s, 160
+  ret i1 %r
+}
+
+define i1 @lshr_pow2_sgt(i8 %x) {
+; CHECK-LABEL: @lshr_pow2_sgt(
+; CHECK-NEXT:    [[S:%.*]] = lshr i8 -128, [[X:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp sgt i8 [[S]], 3
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %s = lshr i8 128, %x
+  %r = icmp sgt i8 %s, 3
+  ret i1 %r
+}
+
 declare void @use(i8)