Cleanup PPC(64) i32 -> float/double conversion

The existing SINT_TO_FP code for i32 -> float/double conversion was disabled
because it relied on broken EXTSW_32/STD_32 instruction definitions. The
original intent had been to enable these 64-bit instructions to be used on CPUs
that support them even in 32-bit mode.  Unfortunately, this form of lying to
the infrastructure was buggy (as explained in the FIXME comment) and had
therefore been disabled.

This re-enables this functionality, using regular DAG nodes, but only when
compiling in 64-bit mode. The old STD_32/EXTSW_32 definitions (which were dead)
are removed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178438 91177308-0d34-0410-b5e6-96231b3b80d8

6 files changed, 40 insertions, 42 deletions

diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp
index 0574f047c2..bf31029a1d 100644
--- a/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -326,10 +326,8 @@ PPCTargetLowering::PPCTargetLowering(PPCTargetMachine &TM)
     // We cannot do this with Promote because i64 is not a legal type.
     setOperationAction(ISD::FP_TO_UINT, MVT::i32, Custom);
 
-    // FIXME: disable this lowered code.  This generates 64-bit register values,
-    // and we don't model the fact that the top part is clobbered by calls.  We
-    // need to flag these together so that the value isn't live across a call.
-    //setOperationAction(ISD::SINT_TO_FP, MVT::i32, Custom);
+    if (Subtarget->isPPC64())
+      setOperationAction(ISD::SINT_TO_FP, MVT::i32, Custom);
   } else {
     // PowerPC does not have FP_TO_UINT on 32-bit implementations.
     setOperationAction(ISD::FP_TO_UINT, MVT::i32, Expand);
@@ -592,8 +590,6 @@ const char *PPCTargetLowering::getTargetNodeName(unsigned Opcode) const {
   case PPCISD::SRL:             return "PPCISD::SRL";
   case PPCISD::SRA:             return "PPCISD::SRA";
   case PPCISD::SHL:             return "PPCISD::SHL";
-  case PPCISD::EXTSW_32:        return "PPCISD::EXTSW_32";
-  case PPCISD::STD_32:          return "PPCISD::STD_32";
   case PPCISD::CALL:            return "PPCISD::CALL";
   case PPCISD::CALL_NOP:        return "PPCISD::CALL_NOP";
   case PPCISD::MTCTR:           return "PPCISD::MTCTR";
@@ -4817,17 +4813,13 @@ SDValue PPCTargetLowering::LowerSINT_TO_FP(SDValue Op,
   EVT PtrVT = DAG.getTargetLoweringInfo().getPointerTy();
   SDValue FIdx = DAG.getFrameIndex(FrameIdx, PtrVT);
 
-  SDValue Ext64 = DAG.getNode(PPCISD::EXTSW_32, dl, MVT::i32,
-                                Op.getOperand(0));
+  SDValue Ext64 = DAG.getNode(ISD::SIGN_EXTEND, dl, MVT::i64,
+                              Op.getOperand(0));
 
   // STD the extended value into the stack slot.
-  MachineMemOperand *MMO =
-    MF.getMachineMemOperand(MachinePointerInfo::getFixedStack(FrameIdx),
-                            MachineMemOperand::MOStore, 8, 8);
-  SDValue Ops[] = { DAG.getEntryNode(), Ext64, FIdx };
-  SDValue Store =
-    DAG.getMemIntrinsicNode(PPCISD::STD_32, dl, DAG.getVTList(MVT::Other),
-                            Ops, 4, MVT::i64, MMO);
+  SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, Ext64, FIdx,
+                               MachinePointerInfo(), false, false, 0);
+
   // Load the value as a double.
   SDValue Ld = DAG.getLoad(MVT::f64, dl, Store, FIdx, MachinePointerInfo(),
                            false, false, false, 0);
diff --git a/lib/Target/PowerPC/PPCISelLowering.h b/lib/Target/PowerPC/PPCISelLowering.h
index 6296400ec7..bce05a16c6 100644
--- a/lib/Target/PowerPC/PPCISelLowering.h
+++ b/lib/Target/PowerPC/PPCISelLowering.h
@@ -91,10 +91,6 @@ namespace llvm {
       /// code.
       SRL, SRA, SHL,
 
-      /// EXTSW_32 - This is the EXTSW instruction for use with "32-bit"
-      /// registers.
-      EXTSW_32,
-
       /// CALL - A direct function call.
       /// CALL_NOP is a call with the special NOP which follows 64-bit
       /// SVR4 calls.
@@ -234,14 +230,11 @@ namespace llvm {
       /// optimizations due to constant folding.
       VADD_SPLAT,
 
-      /// STD_32 - This is the STD instruction for use with "32-bit" registers.
-      STD_32 = ISD::FIRST_TARGET_MEMORY_OPCODE,
-
       /// CHAIN = STBRX CHAIN, GPRC, Ptr, Type - This is a
       /// byte-swapping store instruction.  It byte-swaps the low "Type" bits of
       /// the GPRC input, then stores it through Ptr.  Type can be either i16 or
       /// i32.
-      STBRX,
+      STBRX = ISD::FIRST_TARGET_MEMORY_OPCODE,
 
       /// GPRC, CHAIN = LBRX CHAIN, Ptr, Type - This is a
       /// byte-swapping load instruction.  It loads "Type" bits, byte swaps it,
diff --git a/lib/Target/PowerPC/PPCInstr64Bit.td b/lib/Target/PowerPC/PPCInstr64Bit.td
index e031dfa398..6cc2260de5 100644
--- a/lib/Target/PowerPC/PPCInstr64Bit.td
+++ b/lib/Target/PowerPC/PPCInstr64Bit.td
@@ -452,10 +452,6 @@ def EXTSH8 : XForm_11<31, 922, (outs G8RC:$rA), (ins G8RC:$rS),
 def EXTSW  : XForm_11<31, 986, (outs G8RC:$rA), (ins G8RC:$rS),
                       "extsw $rA, $rS", IntSimple,
                       [(set i64:$rA, (sext_inreg i64:$rS, i32))]>, isPPC64;
-/// EXTSW_32 - Just like EXTSW, but works on '32-bit' registers.
-def EXTSW_32 : XForm_11<31, 986, (outs GPRC:$rA), (ins GPRC:$rS),
-                      "extsw $rA, $rS", IntSimple,
-                      [(set i32:$rA, (PPCextsw_32 i32:$rS))]>, isPPC64;
 def EXTSW_32_64 : XForm_11<31, 986, (outs G8RC:$rA), (ins GPRC:$rS),
                       "extsw $rA, $rS", IntSimple,
                       [(set i64:$rA, (sext i32:$rS))]>, isPPC64;
@@ -786,15 +782,6 @@ def STDBRX: XForm_8<31, 660, (outs), (ins G8RC:$rS, memrr:$dst),
                    "stdbrx $rS, $dst", LdStStore,
                    [(PPCstbrx i64:$rS, xoaddr:$dst, i64)]>, isPPC64,
                    PPC970_DGroup_Cracked;
-
-// STD_32/STDX_32 - Just like STD/STDX, but uses a '32-bit' input register.
-def STD_32  : DSForm_1<62, 0, (outs), (ins GPRC:$rT, memrix:$dst),
-                       "std $rT, $dst", LdStSTD,
-                       [(PPCstd_32  i32:$rT, ixaddr:$dst)]>, isPPC64;
-def STDX_32  : XForm_8<31, 149, (outs), (ins GPRC:$rT, memrr:$dst),
-                       "stdx $rT, $dst", LdStSTD,
-                       [(PPCstd_32  i32:$rT, xaddr:$dst)]>, isPPC64,
-                       PPC970_DGroup_Cracked;
 }
 
 // Stores with Update (pre-inc).
diff --git a/lib/Target/PowerPC/PPCInstrInfo.td b/lib/Target/PowerPC/PPCInstrInfo.td
index f897a47800..d3d7dc66c9 100644
--- a/lib/Target/PowerPC/PPCInstrInfo.td
+++ b/lib/Target/PowerPC/PPCInstrInfo.td
@@ -105,10 +105,6 @@ def PPCsrl        : SDNode<"PPCISD::SRL"       , SDTIntShiftOp>;
 def PPCsra        : SDNode<"PPCISD::SRA"       , SDTIntShiftOp>;
 def PPCshl        : SDNode<"PPCISD::SHL"       , SDTIntShiftOp>;
 
-def PPCextsw_32   : SDNode<"PPCISD::EXTSW_32"  , SDTIntUnaryOp>;
-def PPCstd_32     : SDNode<"PPCISD::STD_32"    , SDTStore,
-                           [SDNPHasChain, SDNPMayStore]>;
-
 // These are target-independent nodes, but have target-specific formats.
 def callseq_start : SDNode<"ISD::CALLSEQ_START", SDT_PPCCallSeqStart,
                            [SDNPHasChain, SDNPOutGlue]>;
diff --git a/lib/Target/PowerPC/PPCRegisterInfo.cpp b/lib/Target/PowerPC/PPCRegisterInfo.cpp
index ecfa552751..482a3bc939 100644
--- a/lib/Target/PowerPC/PPCRegisterInfo.cpp
+++ b/lib/Target/PowerPC/PPCRegisterInfo.cpp
@@ -68,7 +68,7 @@ PPCRegisterInfo::PPCRegisterInfo(const PPCSubtarget &ST,
   ImmToIdxMap[PPC::LHZ8] = PPC::LHZX8; ImmToIdxMap[PPC::LWZ8] = PPC::LWZX8;
   ImmToIdxMap[PPC::STB8] = PPC::STBX8; ImmToIdxMap[PPC::STH8] = PPC::STHX8;
   ImmToIdxMap[PPC::STW8] = PPC::STWX8; ImmToIdxMap[PPC::STDU] = PPC::STDUX;
-  ImmToIdxMap[PPC::ADDI8] = PPC::ADD8; ImmToIdxMap[PPC::STD_32] = PPC::STDX_32;
+  ImmToIdxMap[PPC::ADDI8] = PPC::ADD8;
 }
 
 /// getPointerRegClass - Return the register class to use to hold pointers.
@@ -522,7 +522,6 @@ PPCRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
   case PPC::LWA:
   case PPC::LD:
   case PPC::STD:
-  case PPC::STD_32:
     isIXAddr = true;
     break;
   }
diff --git a/test/CodeGen/PowerPC/i32-to-float.ll b/test/CodeGen/PowerPC/i32-to-float.ll
new file mode 100644
index 0000000000..0807717e50
--- /dev/null
+++ b/test/CodeGen/PowerPC/i32-to-float.ll
@@ -0,0 +1,31 @@
+; RUN: llc < %s -mtriple=powerpc64-unknown-linux-gnu -mcpu=g5 | FileCheck %s
+target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-f128:128:128-v128:128:128-n32:64"
+target triple = "powerpc64-unknown-linux-gnu"
+
+define float @foo(i32 %a) nounwind {
+entry:
+  %x = sitofp i32 %a to float
+  ret float %x
+
+; CHECK: @foo
+; CHECK: extsw [[REG:[0-9]+]], 3
+; CHECK: std [[REG]],
+; CHECK: lfd [[REG2:[0-9]+]],
+; CHECK: fcfid [[REG3:[0-9]+]], [[REG2]]
+; CHECK: frsp 1, [[REG3]]
+; CHECK: blr
+}
+
+define double @goo(i32 %a) nounwind {
+entry:
+  %x = sitofp i32 %a to double
+  ret double %x
+
+; CHECK: @goo
+; CHECK: extsw [[REG:[0-9]+]], 3
+; CHECK: std [[REG]],
+; CHECK: lfd [[REG2:[0-9]+]],
+; CHECK: fcfid 1, [[REG2]]
+; CHECK: blr
+}
+