Merging r348461:

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r348461 | lebedevri | 2018-12-06 00:11:20 -0800 (Thu, 06 Dec 2018) | 4 lines

[NFC][InstCombine] Add more miscompile tests for foldICmpWithLowBitMaskedVal()

We also have to me aware of vector constants. If at least one element
is -1, we can't transform.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_70@348535 91177308-0d34-0410-b5e6-96231b3b80d8

Author: tstellar

test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-sge-to-icmp-sle.ll

@@ -23,19 +23,6 @@ define i1 @p0(i8 %x) {
   ret i1 %ret
 }
 
-define i1 @pv(i8 %x, i8 %y) {
-; CHECK-LABEL: @pv(
-; CHECK-NEXT:    [[TMP0:%.*]] = lshr i8 -1, [[Y:%.*]]
-; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[TMP0]], [[X:%.*]]
-; CHECK-NEXT:    [[RET:%.*]] = icmp sge i8 [[TMP1]], [[X]]
-; CHECK-NEXT:    ret i1 [[RET]]
-;
-  %tmp0 = lshr i8 -1, %y
-  %tmp1 = and i8 %tmp0, %x
-  %ret = icmp sge i8 %tmp1, %x
-  ret i1 %ret
-}
-
 ; ============================================================================ ;
 ; Vector tests
 ; ============================================================================ ;
@@ -198,3 +185,40 @@ define <2 x i1> @n2(<2 x i8> %x) {
   %ret = icmp sge <2 x i8> %tmp0, %x
   ret <2 x i1> %ret
 }
+
+; ============================================================================ ;
+; Potential miscompiles.
+; ============================================================================ ;
+
+define i1 @nv(i8 %x, i8 %y) {
+; CHECK-LABEL: @nv(
+; CHECK-NEXT:    [[TMP0:%.*]] = lshr i8 -1, [[Y:%.*]]
+; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[TMP0]], [[X:%.*]]
+; CHECK-NEXT:    [[RET:%.*]] = icmp sge i8 [[TMP1]], [[X]]
+; CHECK-NEXT:    ret i1 [[RET]]
+;
+  %tmp0 = lshr i8 -1, %y
+  %tmp1 = and i8 %tmp0, %x
+  %ret = icmp sge i8 %tmp1, %x
+  ret i1 %ret
+}
+
+define <2 x i1> @n3_vec(<2 x i8> %x) {
+; CHECK-LABEL: @n3_vec(
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt <2 x i8> [[X:%.*]], <i8 4, i8 0>
+; CHECK-NEXT:    ret <2 x i1> [[TMP1]]
+;
+  %tmp0 = and <2 x i8> %x, <i8 3, i8 -1>
+  %ret = icmp sge <2 x i8> %tmp0, %x
+  ret <2 x i1> %ret
+}
+
+define <3 x i1> @n4_vec(<3 x i8> %x) {
+; CHECK-LABEL: @n4_vec(
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt <3 x i8> [[X:%.*]], <i8 4, i8 undef, i8 0>
+; CHECK-NEXT:    ret <3 x i1> [[TMP1]]
+;
+  %tmp0 = and <3 x i8> %x, <i8 3, i8 undef, i8 -1>
+  %ret = icmp sge <3 x i8> %tmp0, %x
+  ret <3 x i1> %ret
+}

test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-slt-to-icmp-sgt.ll

@@ -23,19 +23,6 @@ define i1 @p0(i8 %x) {
   ret i1 %ret
 }
 
-define i1 @pv(i8 %x, i8 %y) {
-; CHECK-LABEL: @pv(
-; CHECK-NEXT:    [[TMP0:%.*]] = lshr i8 -1, [[Y:%.*]]
-; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[TMP0]], [[X:%.*]]
-; CHECK-NEXT:    [[RET:%.*]] = icmp slt i8 [[TMP1]], [[X]]
-; CHECK-NEXT:    ret i1 [[RET]]
-;
-  %tmp0 = lshr i8 -1, %y
-  %tmp1 = and i8 %tmp0, %x
-  %ret = icmp slt i8 %tmp1, %x
-  ret i1 %ret
-}
-
 ; ============================================================================ ;
 ; Vector tests
 ; ============================================================================ ;
@@ -198,3 +185,40 @@ define <2 x i1> @n2(<2 x i8> %x) {
   %ret = icmp slt <2 x i8> %tmp0, %x
   ret <2 x i1> %ret
 }
+
+; ============================================================================ ;
+; Potential miscompiles.
+; ============================================================================ ;
+
+define i1 @nv(i8 %x, i8 %y) {
+; CHECK-LABEL: @nv(
+; CHECK-NEXT:    [[TMP0:%.*]] = lshr i8 -1, [[Y:%.*]]
+; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[TMP0]], [[X:%.*]]
+; CHECK-NEXT:    [[RET:%.*]] = icmp slt i8 [[TMP1]], [[X]]
+; CHECK-NEXT:    ret i1 [[RET]]
+;
+  %tmp0 = lshr i8 -1, %y
+  %tmp1 = and i8 %tmp0, %x
+  %ret = icmp slt i8 %tmp1, %x
+  ret i1 %ret
+}
+
+define <2 x i1> @n3(<2 x i8> %x) {
+; CHECK-LABEL: @n3(
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp sgt <2 x i8> [[X:%.*]], <i8 3, i8 -1>
+; CHECK-NEXT:    ret <2 x i1> [[TMP1]]
+;
+  %tmp0 = and <2 x i8> %x, <i8 3, i8 -1>
+  %ret = icmp slt <2 x i8> %tmp0, %x
+  ret <2 x i1> %ret
+}
+
+define <3 x i1> @n4(<3 x i8> %x) {
+; CHECK-LABEL: @n4(
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp sgt <3 x i8> [[X:%.*]], <i8 3, i8 undef, i8 -1>
+; CHECK-NEXT:    ret <3 x i1> [[TMP1]]
+;
+  %tmp0 = and <3 x i8> %x, <i8 3, i8 undef, i8 -1>
+  %ret = icmp slt <3 x i8> %tmp0, %x
+  ret <3 x i1> %ret
+}