[InstCombine] add tests for icmp-shr. nfc

diff --git a/llvm/test/Transforms/InstCombine/icmp-shr.ll b/llvm/test/Transforms/InstCombine/icmp-shr.ll
index c91010893543ae134ef85ea3c0511ead5dde1f8f..eced3ba0e624d12ad068f846d0f9c638d5419e62 100644 (file)
--- a/llvm/test/Transforms/InstCombine/icmp-shr.ll
+++ b/llvm/test/Transforms/InstCombine/icmp-shr.ll
@@ -1184,3 +1184,125 @@ define i1 @lshr_pow2_slt(i8 %x) {
   %r = icmp slt i8 %s, 3
   ret i1 %r
 }
+
+; (ShiftValC >> X) >s -1 --> X != 0 with ShiftValC < 0
+
+define i1 @lshr_neg_sgt_minus_1(i8 %x) {
+; CHECK-LABEL: @lshr_neg_sgt_minus_1(
+; CHECK-NEXT:    [[S:%.*]] = lshr i8 -17, [[X:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp sgt i8 [[S]], -1
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %s = lshr i8 -17, %x
+  %r = icmp sgt i8 %s, -1
+  ret i1 %r
+}
+
+define <2 x i1> @lshr_neg_sgt_minus_1_vector(<2 x i8> %x) {
+; CHECK-LABEL: @lshr_neg_sgt_minus_1_vector(
+; CHECK-NEXT:    [[S:%.*]] = lshr <2 x i8> <i8 -17, i8 -17>, [[X:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp sgt <2 x i8> [[S]], <i8 -1, i8 -1>
+; CHECK-NEXT:    ret <2 x i1> [[R]]
+;
+  %s = lshr <2 x i8> <i8 -17, i8 -17>, %x
+  %r = icmp sgt <2 x i8> %s, <i8 -1, i8 -1>
+  ret <2 x i1> %r
+}
+
+; Negative tests
+
+define i1 @lshr_neg_sgt_minus_1_extra_use(i8 %x) {
+; CHECK-LABEL: @lshr_neg_sgt_minus_1_extra_use(
+; CHECK-NEXT:    [[S:%.*]] = lshr i8 -17, [[X:%.*]]
+; CHECK-NEXT:    call void @use(i8 [[S]])
+; CHECK-NEXT:    [[R:%.*]] = icmp sgt i8 [[S]], -1
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %s = lshr i8 -17, %x
+  call void @use(i8 %s)
+  %r = icmp sgt i8 %s, -1
+  ret i1 %r
+}
+
+define i1 @lshr_neg_sgt_minus_2(i8 %x) {
+; CHECK-LABEL: @lshr_neg_sgt_minus_2(
+; CHECK-NEXT:    [[S:%.*]] = lshr i8 -17, [[X:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp sgt i8 [[S]], -2
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %s = lshr i8 -17, %x
+  %r = icmp sgt i8 %s, -2
+  ret i1 %r
+}
+
+define i1 @lshr_neg_slt_minus_1(i8 %x) {
+; CHECK-LABEL: @lshr_neg_slt_minus_1(
+; CHECK-NEXT:    [[S:%.*]] = lshr i8 -17, [[X:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp slt i8 [[S]], -1
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %s = lshr i8 -17, %x
+  %r = icmp slt i8 %s, -1
+  ret i1 %r
+}
+
+; (ShiftValC >> X) <s 0 --> X == 0 with ShiftValC < 0
+
+define i1 @lshr_neg_slt_zero(i8 %x) {
+; CHECK-LABEL: @lshr_neg_slt_zero(
+; CHECK-NEXT:    [[S:%.*]] = lshr i8 -17, [[X:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp slt i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %s = lshr i8 -17, %x
+  %r = icmp slt i8 %s, 0
+  ret i1 %r
+}
+
+define <2 x i1> @lshr_neg_slt_zero_vector(<2 x i8> %x) {
+; CHECK-LABEL: @lshr_neg_slt_zero_vector(
+; CHECK-NEXT:    [[S:%.*]] = lshr <2 x i8> <i8 -17, i8 -17>, [[X:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp slt <2 x i8> [[S]], zeroinitializer
+; CHECK-NEXT:    ret <2 x i1> [[R]]
+;
+  %s = lshr <2 x i8> <i8 -17, i8 -17>, %x
+  %r = icmp slt <2 x i8> %s, <i8 0, i8 0>
+  ret <2 x i1> %r
+}
+
+; Negative tests
+
+define i1 @lshr_neg_slt_zero_extra_use(i8 %x) {
+; CHECK-LABEL: @lshr_neg_slt_zero_extra_use(
+; CHECK-NEXT:    [[S:%.*]] = lshr i8 -17, [[X:%.*]]
+; CHECK-NEXT:    call void @use(i8 [[S]])
+; CHECK-NEXT:    [[R:%.*]] = icmp slt i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %s = lshr i8 -17, %x
+  call void @use(i8 %s)
+  %r = icmp slt i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @lshr_neg_slt_non-zero(i8 %x) {
+; CHECK-LABEL: @lshr_neg_slt_non-zero(
+; CHECK-NEXT:    [[S:%.*]] = lshr i8 -17, [[X:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp slt i8 [[S]], 2
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %s = lshr i8 -17, %x
+  %r = icmp slt i8 %s, 2
+  ret i1 %r
+}
+
+define i1 @lshr_neg_sgt_zero(i8 %x) {
+; CHECK-LABEL: @lshr_neg_sgt_zero(
+; CHECK-NEXT:    [[S:%.*]] = lshr i8 -17, [[X:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp sgt i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %s = lshr i8 -17, %x
+  %r = icmp sgt i8 %s, 0
+  ret i1 %r
+}