From 0076ca0da9bd124506d50c5e6d9616daf0bbf679 Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Tue, 12 Dec 2006 19:53:13 +0000
Subject: [PATCH] - When expanding a bit_convert whose src operand is also to
 be expanded and its expansion result type is equal to the result type of the
 bit_convert, e.g. (i64 bit_convert (f64 op)) if FP is not legal returns the
 result of the expanded source operand. - Store f32 / f64 may be expanded to a
 single store i32/i64.

llvm-svn: 32490
---
 llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index c0ad928e7a33..ac4f512ea4b4 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -1735,7 +1735,7 @@ SDOperand SelectionDAGLegalize::LegalizeOp(SDOperand Op) {
           }
         } else {
           ExpandOp(Node->getOperand(1), Lo, Hi);
-          IncrementSize = MVT::getSizeInBits(Hi.getValueType())/8;
+          IncrementSize = Hi.Val ? MVT::getSizeInBits(Hi.getValueType())/8 : 0;
 
           if (!TLI.isLittleEndian())
             std::swap(Lo, Hi);
@@ -1743,6 +1743,13 @@ SDOperand SelectionDAGLegalize::LegalizeOp(SDOperand Op) {
 
         Lo = DAG.getStore(Tmp1, Lo, Tmp2, ST->getSrcValue(),
                           ST->getSrcValueOffset());
+
+        if (Hi.Val == NULL) {
+          // Must be int <-> float one-to-one expansion.
+          Result = Lo;
+          break;
+        }
+
         Tmp2 = DAG.getNode(ISD::ADD, Tmp2.getValueType(), Tmp2,
                            getIntPtrConstant(IncrementSize));
         assert(isTypeLegal(Tmp2.getValueType()) &&
@@ -4593,7 +4600,14 @@ void SelectionDAGLegalize::ExpandOp(SDOperand Op, SDOperand &Lo, SDOperand &Hi){
     // f32 / f64 must be expanded to i32 / i64.
     if (VT == MVT::f32 || VT == MVT::f64) {
       Lo = DAG.getNode(ISD::BIT_CONVERT, NVT, Node->getOperand(0));
-      Hi = SDOperand();
+      break;
+    }
+
+    // If source operand will be expanded to the same type as VT, i.e.
+    // i64 <- f64, i32 <- f32, expand the source operand instead.
+    MVT::ValueType VT0 = Node->getOperand(0).getValueType();
+    if (getTypeAction(VT0) == Expand && TLI.getTypeToTransformTo(VT0) == VT) {
+      ExpandOp(Node->getOperand(0), Lo, Hi);
       break;
     }