Implement FpSET_ST1_*.

llvm-svn: 64186

1 files changed, 15 insertions, 1 deletions

diff --git a/llvm/lib/Target/X86/X86FloatingPoint.cpp b/llvm/lib/Target/X86/X86FloatingPoint.cpp
index 39082284aad..0c98205980d 100644
--- a/llvm/lib/Target/X86/X86FloatingPoint.cpp
+++ b/llvm/lib/Target/X86/X86FloatingPoint.cpp
@@ -982,7 +982,21 @@ void FPS::handleSpecialFP(MachineBasicBlock::iterator &I) {
   case X86::FpSET_ST0_32:
   case X86::FpSET_ST0_64:
   case X86::FpSET_ST0_80:
-    assert(StackTop == 1 && "Stack should have one element on it to return!");
+    assert((StackTop == 1 || StackTop == 2)
+           && "Stack should have one or two element on it to return!");
+    --StackTop;   // "Forget" we have something on the top of stack!
+    break;
+  case X86::FpSET_ST1_32:
+  case X86::FpSET_ST1_64:
+  case X86::FpSET_ST1_80:
+    // StackTop can be 1 if a FpSET_ST0_* was before this. Exchange them.
+    if (StackTop == 1) {
+      BuildMI(*MBB, I, TII->get(X86::XCH_F)).addReg(X86::ST1);
+      NumFXCH++;
+      StackTop = 0;
+      break;
+    }
+    assert(StackTop == 2 && "Stack should have two element on it to return!");
     --StackTop;   // "Forget" we have something on the top of stack!
     break;
   case X86::MOV_Fp3232: