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Diffstat (limited to 'test/CodeGen/X86/vec_trunc_sext.ll')
| -rw-r--r-- | test/CodeGen/X86/vec_trunc_sext.ll | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/test/CodeGen/X86/vec_trunc_sext.ll b/test/CodeGen/X86/vec_trunc_sext.ll new file mode 100644 index 0000000..3c446bb --- /dev/null +++ b/test/CodeGen/X86/vec_trunc_sext.ll @@ -0,0 +1,30 @@ +; RUN: llc %s -mtriple=x86_64-unknown-unknown -mattr='-sse4.1' -o - | FileCheck %s -check-prefix=NO_SSE_41 +; RUN: llc %s -mtriple=x86_64-unknown-unknown -mattr='+sse4.1' -o - | FileCheck %s -check-prefix=SSE_41 + +; PR20472 ( http://llvm.org/bugs/show_bug.cgi?id=20472 ) +; When sexting a trunc'd vector value, we can't eliminate the zext. +; If we don't have SSE4.1, use punpck. +; If we have SSE4.1, use pmovzx because it combines the load op. +; There may be a better way to do this using pshufb + pmovsx, +; but that is beyond our current codegen capabilities. + +define <4 x i32> @trunc_sext(<4 x i16>* %in) { + %load = load <4 x i16>* %in + %trunc = trunc <4 x i16> %load to <4 x i8> + %sext = sext <4 x i8> %trunc to <4 x i32> + ret <4 x i32> %sext + +; NO_SSE_41-LABEL: trunc_sext: +; NO_SSE_41: movq (%rdi), %xmm0 +; NO_SSE_41-NEXT: punpcklwd %xmm0, %xmm0 +; NO_SSE_41-NEXT: pslld $24, %xmm0 +; NO_SSE_41-NEXT: psrad $24, %xmm0 +; NO_SSE_41-NEXT: retq + +; SSE_41-LABEL: trunc_sext: +; SSE_41: pmovzxwd (%rdi), %xmm0 +; SSE_41-NEXT: pslld $24, %xmm0 +; SSE_41-NEXT: psrad $24, %xmm0 +; SSE_41-NEXT: retq +} + |