Implement initial support for return values from call instructions

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@4924 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 14 insertions, 0 deletions

diff --git a/lib/Target/X86/InstSelectSimple.cpp b/lib/Target/X86/InstSelectSimple.cpp
index 55bf65b2f5..2f701ed8d3 100644
--- a/lib/Target/X86/InstSelectSimple.cpp
+++ b/lib/Target/X86/InstSelectSimple.cpp
@@ -430,6 +430,20 @@ ISel::visitCallInst (CallInst & CI)
   // Adjust the stack by `bytesPushed' amount if non-zero
   if (bytesPushed > 0)
     BuildMI (BB, X86::ADDri32, 2).addReg(X86::ESP).addZImm(bytesPushed);
+
+  // If there is a return value, scavenge the result from the location the call
+  // leaves it in...
+  //
+  switch (getClass(CI.getType())) {
+  case cInt:
+    BuildMI(BB, X86::MOVrr32, 1, getReg(CI)).addReg(X86::EAX);
+    break;
+
+  default:
+    std::cerr << "Cannot get return value for call of type '"
+              << *CI.getType() << "'\n";
+    visitInstruction(CI);
+  }
 }
 
 /// visitSimpleBinary - Implement simple binary operators for integral types...