Operand of asm("call") (the callee function) is represented

as "X" constraint and "P" modifier on x86.  Make this work.
(Change may not be sufficient to fix it for non-Darwin, but
I'm pretty sure it won't break anything.)
gcc.apple/asm-block-32.c
gcc.apple/asm-block-33.c



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74967 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/SelectionDAG/TargetLowering.cpp

@@ -2405,11 +2405,24 @@ void TargetLowering::ComputeConstraintToUse(AsmOperandInfo &OpInfo,
   
   // 'X' matches anything.
   if (OpInfo.ConstraintCode == "X" && OpInfo.CallOperandVal) {
+    // Look through bitcasts over functions.  In the context of an asm
+    // argument we don't care about bitcasting function types; the parameters
+    // to the function, if any, will have been handled elsewhere.
+    Value *v = OpInfo.CallOperandVal;
+    ConstantExpr *CE = NULL;
+    while ((CE = dyn_cast<ConstantExpr>(v)) &&
+           CE->getOpcode()==Instruction::BitCast)
+      v = CE->getOperand(0);
+    if (!isa<Function>(v))
+      v = OpInfo.CallOperandVal;
     // Labels and constants are handled elsewhere ('X' is the only thing
-    // that matches labels).
+    // that matches labels).  For Functions, the type here is the type of
-    if (isa<BasicBlock>(OpInfo.CallOperandVal) ||
+    // the result, which is not what we want to look at; leave them alone
-        isa<ConstantInt>(OpInfo.CallOperandVal))
+    // (minus any bitcasts).
+    if (isa<BasicBlock>(v) || isa<ConstantInt>(v) || isa<Function>(v)) {
+      OpInfo.CallOperandVal = v;
       return;
+    }
     
     // Otherwise, try to resolve it to something we know about by looking at
     // the actual operand type.