Merge pull request rust-lang#63 from phil-opp/x86-intrcc-nosse-fix

x86 interrupt calling convention: only save xmm registers if the target supports SSE

Author: alexcrichton

lib/Target/X86/X86CallingConv.td

@@ -1074,6 +1074,8 @@ def CSR_32_AllRegs_AVX512 : CalleeSavedRegs<(add CSR_32_AllRegs,
                                                  (sequence "K%u", 0, 7))>;
 
 def CSR_64_AllRegs     : CalleeSavedRegs<(add CSR_64_MostRegs, RAX)>;
+def CSR_64_AllRegs_NoSSE : CalleeSavedRegs<(add RAX, RBX, RCX, RDX, RSI, RDI, R8, R9,
+                                                R10, R11, R12, R13, R14, R15, RBP)>;
 def CSR_64_AllRegs_AVX : CalleeSavedRegs<(sub (add CSR_64_MostRegs, RAX,
                                                    (sequence "YMM%u", 0, 15)),
                                               (sequence "XMM%u", 0, 15))>;

lib/Target/X86/X86RegisterInfo.cpp

@@ -337,7 +337,9 @@ X86RegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
         return CSR_64_AllRegs_AVX512_SaveList;
       if (HasAVX)
         return CSR_64_AllRegs_AVX_SaveList;
-      return CSR_64_AllRegs_SaveList;
+      if (HasSSE)
+        return CSR_64_AllRegs_SaveList;
+      return CSR_64_AllRegs_NoSSE_SaveList;
     } else {
       if (HasAVX512)
         return CSR_32_AllRegs_AVX512_SaveList;
@@ -447,7 +449,9 @@ X86RegisterInfo::getCallPreservedMask(const MachineFunction &MF,
         return CSR_64_AllRegs_AVX512_RegMask;
       if (HasAVX)
         return CSR_64_AllRegs_AVX_RegMask;
-      return CSR_64_AllRegs_RegMask;
+      if (HasSSE)
+        return CSR_64_AllRegs_RegMask;
+      return CSR_64_AllRegs_NoSSE_RegMask;
     } else {
       if (HasAVX512)
         return CSR_32_AllRegs_AVX512_RegMask;

test/CodeGen/X86/x86-64-intrcc-nosse.ll

@@ -0,0 +1,19 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=x86_64-unknown-unknown -mattr=-sse < %s | FileCheck %s
+
+%struct.interrupt_frame = type { i64, i64, i64, i64, i64 }
+
+@llvm.used = appending global [1 x i8*] [i8* bitcast (void (%struct.interrupt_frame*, i64)* @test_isr_sse_clobbers to i8*)], section "llvm.metadata"
+
+; Clobbered SSE must not be saved when the target doesn't support SSE
+define x86_intrcc void @test_isr_sse_clobbers(%struct.interrupt_frame* %frame, i64 %ecode) {
+  ; CHECK-LABEL: test_isr_sse_clobbers:
+  ; CHECK:       # BB#0:
+  ; CHECK-NEXT:    cld
+  ; CHECK-NEXT:    #APP
+  ; CHECK-NEXT:    #NO_APP
+  ; CHECK-NEXT:    addq $8, %rsp
+  ; CHECK-NEXT:    iretq
+  call void asm sideeffect "", "~{xmm0},~{xmm6}"()
+  ret void
+}