AMDGPU: Remove dx10-clamp from subtarget features

Since this can be set with s_setreg*, it should not be a subtarget
property. Set a default based on the calling convention, and Introduce
a new amdgpu-dx10-clamp attribute to override this if desired.

Also introduce a new amdgpu-ieee attribute to match.

The values need to match to allow inlining. I think it is OK for the
caller's dx10-clamp attribute to override the callee, but there
doesn't appear to be the infrastructure to do this currently without
definining the attribute in the generic Attributes.td.

Eventually the calling convention lowering will need to insert a mode
switch somewhere for these.

llvm-svn: 357302

1 files changed, 18 insertions, 5 deletions

diff --git a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
index 8437e4bb34e..c3995c2291f 100644
--- a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
@@ -4145,7 +4145,9 @@ SDValue SITargetLowering::lowerFP_ROUND(SDValue Op, SelectionDAG &DAG) const {
 SDValue SITargetLowering::lowerFMINNUM_FMAXNUM(SDValue Op,
                                                SelectionDAG &DAG) const {
   EVT VT = Op.getValueType();
-  bool IsIEEEMode = Subtarget->enableIEEEBit(DAG.getMachineFunction());
+  const MachineFunction &MF = DAG.getMachineFunction();
+  const SIMachineFunctionInfo *Info = MF.getInfo<SIMachineFunctionInfo>();
+  bool IsIEEEMode = Info->getMode().IEEE;
 
   // FIXME: Assert during eslection that this is only selected for
   // ieee_mode. Currently a combine can produce the ieee version for non-ieee
@@ -8300,9 +8302,12 @@ SDValue SITargetLowering::performFPMed3ImmCombine(SelectionDAG &DAG,
   if (Cmp == APFloat::cmpGreaterThan)
     return SDValue();
 
+  const MachineFunction &MF = DAG.getMachineFunction();
+  const SIMachineFunctionInfo *Info = MF.getInfo<SIMachineFunctionInfo>();
+
   // TODO: Check IEEE bit enabled?
   EVT VT = Op0.getValueType();
-  if (Subtarget->enableDX10Clamp()) {
+  if (Info->getMode().DX10Clamp) {
     // If dx10_clamp is enabled, NaNs clamp to 0.0. This is the same as the
     // hardware fmed3 behavior converting to a min.
     // FIXME: Should this be allowing -0.0?
@@ -8436,9 +8441,12 @@ SDValue SITargetLowering::performFMed3Combine(SDNode *N,
     return DAG.getNode(AMDGPUISD::CLAMP, SL, VT, Src2);
   }
 
+  const MachineFunction &MF = DAG.getMachineFunction();
+  const SIMachineFunctionInfo *Info = MF.getInfo<SIMachineFunctionInfo>();
+
   // FIXME: dx10_clamp behavior assumed in instcombine. Should we really bother
   // handling no dx10-clamp?
-  if (Subtarget->enableDX10Clamp()) {
+  if (Info->getMode().DX10Clamp) {
     // If NaNs is clamped to 0, we are free to reorder the inputs.
 
     if (isa<ConstantFPSDNode>(Src0) && !isa<ConstantFPSDNode>(Src1))
@@ -9128,11 +9136,13 @@ SDValue SITargetLowering::performClampCombine(SDNode *N,
   if (!CSrc)
     return SDValue();
 
+  const MachineFunction &MF = DCI.DAG.getMachineFunction();
   const APFloat &F = CSrc->getValueAPF();
   APFloat Zero = APFloat::getZero(F.getSemantics());
   APFloat::cmpResult Cmp0 = F.compare(Zero);
   if (Cmp0 == APFloat::cmpLessThan ||
-      (Cmp0 == APFloat::cmpUnordered && Subtarget->enableDX10Clamp())) {
+      (Cmp0 == APFloat::cmpUnordered &&
+       MF.getInfo<SIMachineFunctionInfo>()->getMode().DX10Clamp)) {
     return DCI.DAG.getConstantFP(Zero, SDLoc(N), N->getValueType(0));
   }
 
@@ -9967,7 +9977,10 @@ bool SITargetLowering::isKnownNeverNaNForTargetNode(SDValue Op,
                                                     bool SNaN,
                                                     unsigned Depth) const {
   if (Op.getOpcode() == AMDGPUISD::CLAMP) {
-    if (Subtarget->enableDX10Clamp())
+    const MachineFunction &MF = DAG.getMachineFunction();
+    const SIMachineFunctionInfo *Info = MF.getInfo<SIMachineFunctionInfo>();
+
+    if (Info->getMode().DX10Clamp)
       return true; // Clamped to 0.
     return DAG.isKnownNeverNaN(Op.getOperand(0), SNaN, Depth + 1);
   }