[SelectionDAG] Unary vector constant folding integer legality fixes
This patch fixes issues with vector constant folding not correctly handling scalar input operands if they require implicit truncation - this was tested with llvm-stress as recommended by Patrik H Hagglund.
The patch ensures that integer input scalars from a build vector are correctly truncated before folding, and that constant integer scalar results are promoted to a legal type before inclusion in the new folded build vector.
I have added another crash test case and also a test for UINT_TO_FP / SINT_TO_FP using an non-truncated scalar input, which was failing before this patch.
Differential Revision: http://reviews.llvm.org/D9282
llvm-svn: 236308
diff --git a/llvm/test/CodeGen/X86/fold-vector-bv-crash.ll b/llvm/test/CodeGen/X86/fold-vector-bv-crash.ll
new file mode 100644
index 0000000..8c72afb
--- /dev/null
+++ b/llvm/test/CodeGen/X86/fold-vector-bv-crash.ll
@@ -0,0 +1,17 @@
+; RUN: llc < %s -mtriple=i686-unknown -mattr=+avx
+; RUN: llc < %s -mtriple=x86_64-unknown -mattr=+avx
+
+;
+; llvm-stress generated crash case due to build_vector implicit
+; truncation bug from constant folding after legalization.
+;
+
+@G = external global i32
+
+define void @bv_crash_test() {
+ %I = insertelement <4 x i64> zeroinitializer, i64 15910, i32 0
+ %Tr = trunc <4 x i64> %I to <4 x i8>
+ %Bc = bitcast <4 x i8> %Tr to i32
+ store volatile i32 %Bc, i32* @G
+ ret void
+}