Fix gcc.c-torture/compile/920520-1.c by inserting bitconverts

for strange asm conditions earlier.  In this case, we have a
double being passed in an integer reg class.  Convert to like
sized integer register so that we allocate the right number 
for the class (two i32's for the f64 in this case).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57862 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 41 insertions, 7 deletions

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
index 0fba3a403b..ed9edf1067 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
@@ -512,11 +512,8 @@ static SDValue getCopyFromParts(SelectionDAG &DAG,
 /// getCopyToParts - Create a series of nodes that contain the specified value
 /// split into legal parts.  If the parts contain more bits than Val, then, for
 /// integers, ExtendKind can be used to specify how to generate the extra bits.
-static void getCopyToParts(SelectionDAG &DAG,
-                           SDValue Val,
-                           SDValue *Parts,
-                           unsigned NumParts,
-                           MVT PartVT,
+static void getCopyToParts(SelectionDAG &DAG, SDValue Val,
+                           SDValue *Parts, unsigned NumParts, MVT PartVT,
                            ISD::NodeType ExtendKind = ISD::ANY_EXTEND) {
   TargetLowering &TLI = DAG.getTargetLoweringInfo();
   MVT PtrVT = TLI.getPointerTy();
@@ -4497,11 +4494,37 @@ GetRegistersForValue(SDISelAsmOperandInfo &OpInfo,
                                      OpInfo.ConstraintVT);
 
   unsigned NumRegs = 1;
-  if (OpInfo.ConstraintVT != MVT::Other)
+  if (OpInfo.ConstraintVT != MVT::Other) {
+    // If this is a FP input in an integer register (or visa versa) insert a bit
+    // cast of the input value.  More generally, handle any case where the input
+    // value disagrees with the register class we plan to stick this in.
+    if (OpInfo.Type == InlineAsm::isInput &&
+        PhysReg.second && !PhysReg.second->hasType(OpInfo.ConstraintVT)) {
+      // Try to convert to the first MVT that the reg class contains.  If the
+      // types are identical size, use a bitcast to convert (e.g. two differing
+      // vector types).
+      MVT RegVT = *PhysReg.second->vt_begin();
+      if (RegVT.getSizeInBits() == OpInfo.ConstraintVT.getSizeInBits()) {
+        OpInfo.CallOperand = DAG.getNode(ISD::BIT_CONVERT, RegVT,
+                                         OpInfo.CallOperand);
+        OpInfo.ConstraintVT = RegVT;
+      } else if (RegVT.isInteger() && OpInfo.ConstraintVT.isFloatingPoint()) {
+        // If the input is a FP value and we want it in FP registers, do a
+        // bitcast to the corresponding integer type.  This turns an f64 value
+        // into i64, which can be passed with two i32 values on a 32-bit
+        // machine.
+        RegVT = MVT::getIntegerVT(OpInfo.ConstraintVT.getSizeInBits());
+        OpInfo.CallOperand = DAG.getNode(ISD::BIT_CONVERT, RegVT,
+                                         OpInfo.CallOperand);
+        OpInfo.ConstraintVT = RegVT;
+      }
+    }
+    
     NumRegs = TLI.getNumRegisters(OpInfo.ConstraintVT);
+  }
+  
   MVT RegVT;
   MVT ValueVT = OpInfo.ConstraintVT;
-  
 
   // If this is a constraint for a specific physical register, like {r17},
   // assign it now.
diff --git a/test/CodeGen/X86/2008-10-20-AsmDoubleInI32.ll b/test/CodeGen/X86/2008-10-20-AsmDoubleInI32.ll
new file mode 100644
index 0000000000..33e8c49277
--- /dev/null
+++ b/test/CodeGen/X86/2008-10-20-AsmDoubleInI32.ll
@@ -0,0 +1,11 @@
+; RUN: llvm-as < %s | llc -march=x86
+; RUN: llvm-as < %s | llc -march=x86-64
+
+; from gcc.c-torture/compile/920520-1.c
+
+define i32 @g() nounwind {
+entry:
+	call void asm sideeffect "$0", "r"(double 1.500000e+00) nounwind
+	ret i32 0
+}
+