From c7c77297e28189c3c3bccd6e261a84970704b760 Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Tue, 4 Nov 2008 19:57:48 +0000
Subject: [PATCH] Custom lower bit_convert i64 -> f64 into FMDRR. This is now
 happening with legalizetypes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58714 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/ARM/ARMISelLowering.cpp | 21 ++++++++++++---------
 test/CodeGen/ARM/fixunsdfdi.ll     | 29 +++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+), 9 deletions(-)
 create mode 100644 test/CodeGen/ARM/fixunsdfdi.ll

diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 14c4526d1a0..721213ddc10 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -214,7 +214,7 @@ ARMTargetLowering::ARMTargetLowering(TargetMachine &TM)
   setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1, Expand);
 
   if (!UseSoftFloat && Subtarget->hasVFP2() && !Subtarget->isThumb())
-    // Turn f64->i64 into FMRRD iff target supports vfp2.
+    // Turn f64->i64 into FMRRD, i64 -> f64 to FMDRR iff target supports vfp2.
     setOperationAction(ISD::BIT_CONVERT, MVT::i64, Custom);
 
   // We want to custom lower some of our intrinsics.
@@ -1349,13 +1349,19 @@ ARMTargetLowering::EmitTargetCodeForMemcpy(SelectionDAG &DAG,
 }
 
 static SDNode *ExpandBIT_CONVERT(SDNode *N, SelectionDAG &DAG) {
-  // Turn f64->i64 into FMRRD.
-  assert(N->getValueType(0) == MVT::i64 &&
-         N->getOperand(0).getValueType() == MVT::f64);
-  
   SDValue Op = N->getOperand(0);
+  if (N->getValueType(0) == MVT::f64) {
+    // Turn i64->f64 into FMDRR.
+    SDValue Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Op,
+                             DAG.getConstant(0, MVT::i32));
+    SDValue Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Op,
+                             DAG.getConstant(1, MVT::i32));
+    return DAG.getNode(ARMISD::FMDRR, MVT::f64, Lo, Hi).getNode();
+  }
+  
+  // Turn f64->i64 into FMRRD.
   SDValue Cvt = DAG.getNode(ARMISD::FMRRD, DAG.getVTList(MVT::i32, MVT::i32),
-                              &Op, 1);
+                            &Op, 1);
   
   // Merge the pieces into a single i64 value.
   return DAG.getNode(ISD::BUILD_PAIR, MVT::i64, Cvt, Cvt.getValue(1)).getNode();
@@ -1417,9 +1423,6 @@ SDValue ARMTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) {
   case ISD::FRAMEADDR:     break;
   case ISD::GLOBAL_OFFSET_TABLE: return LowerGLOBAL_OFFSET_TABLE(Op, DAG);
   case ISD::INTRINSIC_WO_CHAIN: return LowerINTRINSIC_WO_CHAIN(Op, DAG);
-      
-      
-  // FIXME: Remove these when LegalizeDAGTypes lands.
   case ISD::BIT_CONVERT:   return SDValue(ExpandBIT_CONVERT(Op.getNode(), DAG), 0);
   case ISD::SRL:
   case ISD::SRA:           return SDValue(ExpandSRx(Op.getNode(), DAG,Subtarget),0);
diff --git a/test/CodeGen/ARM/fixunsdfdi.ll b/test/CodeGen/ARM/fixunsdfdi.ll
new file mode 100644
index 00000000000..d3038b9af76
--- /dev/null
+++ b/test/CodeGen/ARM/fixunsdfdi.ll
@@ -0,0 +1,29 @@
+; RUN: llvm-as < %s | llc -march=arm -mattr=+vfp2
+; RUN: llvm-as < %s | llc -march=arm -mattr=vfp2 | not grep fstd
+
+define hidden i64 @__fixunsdfdi(double %x) nounwind readnone {
+entry:
+	%x14 = bitcast double %x to i64		; <i64> [#uses=1]
+	br i1 true, label %bb3, label %bb10
+
+bb3:		; preds = %entry
+	br i1 true, label %bb5, label %bb7
+
+bb5:		; preds = %bb3
+	%u.in.mask = and i64 %x14, -4294967296		; <i64> [#uses=1]
+	%.ins = or i64 0, %u.in.mask		; <i64> [#uses=1]
+	%0 = bitcast i64 %.ins to double		; <double> [#uses=1]
+	%1 = sub double %x, %0		; <double> [#uses=1]
+	%2 = fptosi double %1 to i32		; <i32> [#uses=1]
+	%3 = add i32 %2, 0		; <i32> [#uses=1]
+	%4 = zext i32 %3 to i64		; <i64> [#uses=1]
+	%5 = shl i64 %4, 32		; <i64> [#uses=1]
+	%6 = or i64 %5, 0		; <i64> [#uses=1]
+	ret i64 %6
+
+bb7:		; preds = %bb3
+	ret i64 0
+
+bb10:		; preds = %entry
+	ret i64 0
+}