[ConstnatFolding] Teach the folder how to fold ConstantVector
A ConstantVector can have ConstantExpr operands and vice versa.
However, the folder had no ability to fold ConstantVectors which, in
some cases, was an optimization barrier.
Instead, rephrase the folder in terms of Constants instead of
ConstantExprs and teach callers how to deal with failure.
llvm-svn: 277099
diff --git a/llvm/test/Transforms/InstCombine/icmp-vec.ll b/llvm/test/Transforms/InstCombine/icmp-vec.ll
index 6fe3f631..f831e2b 100644
--- a/llvm/test/Transforms/InstCombine/icmp-vec.ll
+++ b/llvm/test/Transforms/InstCombine/icmp-vec.ll
@@ -159,11 +159,9 @@
ret <2 x i1> %cmp
}
-; If we can't determine if a constant element is min/max (eg, it's a ConstantExpr), do nothing.
-
define <2 x i1> @PR27756_1(<2 x i8> %a) {
; CHECK-LABEL: @PR27756_1(
-; CHECK-NEXT: [[CMP:%.*]] = icmp sle <2 x i8> %a, <i8 bitcast (<2 x i4> <i4 1, i4 2> to i8), i8 0>
+; CHECK-NEXT: [[CMP:%.*]] = icmp slt <2 x i8> %a, <i8 34, i8 1>
; CHECK-NEXT: ret <2 x i1> [[CMP]]
;
%cmp = icmp sle <2 x i8> %a, <i8 bitcast (<2 x i4> <i4 1, i4 2> to i8), i8 0>