diff --git a/llvm/test/CodeGen/X86/load-combine.ll b/llvm/test/CodeGen/X86/load-combine.ll index 7f8115dc1ce38..7e4e11fcc75c2 100644 --- a/llvm/test/CodeGen/X86/load-combine.ll +++ b/llvm/test/CodeGen/X86/load-combine.ll @@ -1282,3 +1282,36 @@ define i32 @zext_load_i32_by_i8_bswap_shl_16(ptr %arg) { %tmp8 = or i32 %tmp7, %tmp30 ret i32 %tmp8 } + +; FIXME: This is a miscompile. +define i32 @pr80911_vector_load_multiuse(ptr %ptr, ptr %clobber) nounwind { +; CHECK-LABEL: pr80911_vector_load_multiuse: +; CHECK: # %bb.0: +; CHECK-NEXT: pushl %esi +; CHECK-NEXT: movl {{[0-9]+}}(%esp), %ecx +; CHECK-NEXT: movl {{[0-9]+}}(%esp), %edx +; CHECK-NEXT: movl (%edx), %esi +; CHECK-NEXT: movzwl (%edx), %eax +; CHECK-NEXT: movl $0, (%ecx) +; CHECK-NEXT: movl %esi, (%edx) +; CHECK-NEXT: popl %esi +; CHECK-NEXT: retl +; +; CHECK64-LABEL: pr80911_vector_load_multiuse: +; CHECK64: # %bb.0: +; CHECK64-NEXT: movzwl (%rdi), %eax +; CHECK64-NEXT: movl $0, (%rsi) +; CHECK64-NEXT: movl (%rdi), %ecx +; CHECK64-NEXT: movl %ecx, (%rdi) +; CHECK64-NEXT: retq + %load = load <4 x i8>, ptr %ptr, align 16 + store i32 0, ptr %clobber + store <4 x i8> %load, ptr %ptr, align 16 + %e1 = extractelement <4 x i8> %load, i64 1 + %e1.ext = zext i8 %e1 to i32 + %e1.ext.shift = shl nuw nsw i32 %e1.ext, 8 + %e0 = extractelement <4 x i8> %load, i64 0 + %e0.ext = zext i8 %e0 to i32 + %res = or i32 %e1.ext.shift, %e0.ext + ret i32 %res +}