[X86] When using Win64 ABI, exit with error if SSE is disabled for varargs

We need XMM registers to handle varargs with the Win64 ABI. Before we would
silently generate bad code resulting in an assertion failure elsewhere in the
backend.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357317 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index a5691cdfc6aa507f9aaa043640160f3bc73b884a..6f9caf1d0bbd97a76fa90b6ca71a88c956445f9d 100644 (file)
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -3780,6 +3780,9 @@ X86TargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
     } else if (VA.isRegLoc()) {
       RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
       if (isVarArg && IsWin64) {
+        if (!Subtarget.hasSSE1())
+          errorUnsupported(
+              DAG, dl, "Win64 ABI varargs functions require SSE to be enabled");
         // Win64 ABI requires argument XMM reg to be copied to the corresponding
         // shadow reg if callee is a varargs function.
         unsigned ShadowReg = 0;

diff --git a/test/CodeGen/X86/win64-nosse-error.ll b/test/CodeGen/X86/win64-nosse-error.ll
new file mode 100644 (file)
index 0000000..0d22adf
--- /dev/null
+++ b/test/CodeGen/X86/win64-nosse-error.ll
@@ -0,0 +1,17 @@
+; RUN: not --crash llc %s -mattr="-sse" 2>&1 | FileCheck %s
+
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-windows-macho"
+
+; Function Attrs: noimplicitfloat noinline noredzone nounwind optnone
+define void @crash() #0 {
+  call void (i32*, ...) @func(i32* null, double undef)
+  ret void
+}
+; CHECK: in function crash void (): Win64 ABI varargs functions require SSE to be enabled
+; Function Attrs: noimplicitfloat noredzone
+declare void @func(i32*, ...)
+
+attributes #0 = { "target-cpu"="x86-64" "target-features"="-sse"}
+
+