From e2b861f7d91c09115cd637614b1bc5f5154bce1d Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Mon, 10 Aug 2009 20:25:59 +0000
Subject: [PATCH] Handle the constantfp created during post-legalization dag
 combiner phase.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78594 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/ARM/ARMISelDAGToDAG.cpp        | 18 ++++++++++++++++++
 test/CodeGen/Thumb2/2009-08-10-ISelBug.ll | 15 +++++++++++++++
 2 files changed, 33 insertions(+)
 create mode 100644 test/CodeGen/Thumb2/2009-08-10-ISelBug.ll

diff --git a/lib/Target/ARM/ARMISelDAGToDAG.cpp b/lib/Target/ARM/ARMISelDAGToDAG.cpp
index 3304900c9f2..823ae2f10e8 100644
--- a/lib/Target/ARM/ARMISelDAGToDAG.cpp
+++ b/lib/Target/ARM/ARMISelDAGToDAG.cpp
@@ -988,6 +988,24 @@ SDNode *ARMDAGToDAGISel::Select(SDValue Op) {
     // Other cases are autogenerated.
     break;
   }
+  case ISD::ConstantFP: {
+    ConstantFPSDNode *CFP = cast<ConstantFPSDNode>(N);
+    MVT VT = CFP->getValueType(0);
+    ConstantFP *LLVMC = const_cast<ConstantFP*>(CFP->getConstantFPValue());
+    SDValue CPIdx = CurDAG->getTargetConstantPool(LLVMC, TLI.getPointerTy());
+    SDNode *ResNode;
+    SDValue Ops[] = {
+      CPIdx, 
+      CurDAG->getTargetConstant(0, MVT::i32),
+      getAL(CurDAG),
+      CurDAG->getRegister(0, MVT::i32),
+      CurDAG->getEntryNode()
+    };
+    unsigned Opc = (VT == MVT::f32) ? ARM::FLDS : ARM::FLDD;
+    ResNode=CurDAG->getTargetNode(Opc, dl, VT, MVT::Other, Ops, 5);
+    ReplaceUses(Op, SDValue(ResNode, 0));
+    return NULL;
+  }
   case ISD::FrameIndex: {
     // Selects to ADDri FI, 0 which in turn will become ADDri SP, imm.
     int FI = cast<FrameIndexSDNode>(N)->getIndex();
diff --git a/test/CodeGen/Thumb2/2009-08-10-ISelBug.ll b/test/CodeGen/Thumb2/2009-08-10-ISelBug.ll
new file mode 100644
index 00000000000..4c07aa0b151
--- /dev/null
+++ b/test/CodeGen/Thumb2/2009-08-10-ISelBug.ll
@@ -0,0 +1,15 @@
+; RUN: llvm-as < %s | llc -mtriple=thumbv7-apple-darwin -mattr=+vfp2
+
+define arm_apcscc float @t1(i32 %v0) nounwind {
+entry:
+	store i32 undef, i32* undef, align 4
+	%0 = load [4 x i8]** undef, align 4		; <[4 x i8]*> [#uses=1]
+	%1 = load i8* undef, align 1		; <i8> [#uses=1]
+	%2 = zext i8 %1 to i32		; <i32> [#uses=1]
+	%3 = getelementptr [4 x i8]* %0, i32 %v0, i32 0		; <i8*> [#uses=1]
+	%4 = load i8* %3, align 1		; <i8> [#uses=1]
+	%5 = zext i8 %4 to i32		; <i32> [#uses=1]
+	%6 = sub i32 %5, %2		; <i32> [#uses=1]
+	%7 = sitofp i32 %6 to float		; <float> [#uses=1]
+	ret float %7
+}