[X86] Fix assertion failure caused by a wrong folding of vector shifts by immediate...

[oota-llvm.git] / test / CodeGen / X86 / vshift-6.ll

diff --git a/test/CodeGen/X86/vshift-6.ll b/test/CodeGen/X86/vshift-6.ll
new file mode 100644 (file)
index 0000000..f50d9a6
--- /dev/null
+++ b/test/CodeGen/X86/vshift-6.ll
@@ -0,0 +1,36 @@
+; RUN: llc < %s -mcpu=corei7 -march=x86-64 -mattr=+sse2  | FileCheck %s
+
+; This test makes sure that the compiler does not crash with an
+; assertion failure when trying to fold a vector shift left
+; by immediate count if the type of the input vector is different
+; to the result type.
+;
+; This happens for example when lowering a shift left of a MVT::v16i8 vector.
+; This is custom lowered into the following sequence:
+;     count << 5
+;     A =  VSHLI(MVT::v8i16, r & (char16)15, 4)
+;     B = BITCAST MVT::v16i8, A
+;     VSELECT(r, B, count);
+;     count += count
+;     C = VSHLI(MVT::v8i16, r & (char16)63, 2)
+;     D = BITCAST MVT::v16i8, C
+;     r = VSELECT(r, C, count);
+;     count += count
+;     VSELECT(r, r+r, count);
+;     count = count << 5;
+;
+; Where 'r' is a vector of type MVT::v16i8, and
+; 'count' is the vector shift count.
+
+define <16 x i8> @do_not_crash(i8*, i32*, i64*, i32, i64, i8) {
+entry:
+  store i8 %5, i8* %0
+  %L5 = load i8* %0
+  %I8 = insertelement <16 x i8> <i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1>, i8 %L5, i32 7
+  %B51 = shl <16 x i8> <i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1>, %I8
+  ret <16 x i8> %B51
+}
+
+; CHECK-LABEL: do_not_crash
+; CHECK: ret
+