R600/SI: Expand fract to floor, then only select V_FRACT on CI

V_FRACT is buggy on SI.

R600-specific code is left intact.

v2: drop the multiclass, use complex VOP3 patterns
llvm-svn: 233075

4 files changed, 32 insertions, 3 deletions

diff --git a/llvm/lib/Target/R600/AMDGPUISelLowering.cpp b/llvm/lib/Target/R600/AMDGPUISelLowering.cpp
index 4707279ce87..62a33fad64b 100644
--- a/llvm/lib/Target/R600/AMDGPUISelLowering.cpp
+++ b/llvm/lib/Target/R600/AMDGPUISelLowering.cpp
@@ -885,9 +885,6 @@ SDValue AMDGPUTargetLowering::LowerINTRINSIC_WO_CHAIN(SDValue Op,
       return LowerIntrinsicIABS(Op, DAG);
     case AMDGPUIntrinsic::AMDGPU_lrp:
       return LowerIntrinsicLRP(Op, DAG);
-    case AMDGPUIntrinsic::AMDGPU_fract:
-    case AMDGPUIntrinsic::AMDIL_fraction: // Legacy name.
-      return DAG.getNode(AMDGPUISD::FRACT, DL, VT, Op.getOperand(1));
 
     case AMDGPUIntrinsic::AMDGPU_clamp:
     case AMDGPUIntrinsic::AMDIL_clamp: // Legacy name.
diff --git a/llvm/lib/Target/R600/R600ISelLowering.cpp b/llvm/lib/Target/R600/R600ISelLowering.cpp
index d4f3145e6ae..06b72179676 100644
--- a/llvm/lib/Target/R600/R600ISelLowering.cpp
+++ b/llvm/lib/Target/R600/R600ISelLowering.cpp
@@ -837,6 +837,10 @@ SDValue R600TargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const
     case Intrinsic::AMDGPU_rsq:
       // XXX - I'm assuming SI's RSQ_LEGACY matches R600's behavior.
       return DAG.getNode(AMDGPUISD::RSQ_LEGACY, DL, VT, Op.getOperand(1));
+
+    case AMDGPUIntrinsic::AMDGPU_fract:
+    case AMDGPUIntrinsic::AMDIL_fraction: // Legacy name.
+      return DAG.getNode(AMDGPUISD::FRACT, DL, VT, Op.getOperand(1));
     }
     // break out of case ISD::INTRINSIC_WO_CHAIN in switch(Op.getOpcode())
     break;
diff --git a/llvm/lib/Target/R600/SIISelLowering.cpp b/llvm/lib/Target/R600/SIISelLowering.cpp
index 16d67022aa8..01fece2694f 100644
--- a/llvm/lib/Target/R600/SIISelLowering.cpp
+++ b/llvm/lib/Target/R600/SIISelLowering.cpp
@@ -928,6 +928,12 @@ SDValue SITargetLowering::LowerINTRINSIC_WO_CHAIN(SDValue Op,
                        Op.getOperand(1),
                        Op.getOperand(2),
                        Op.getOperand(3));
+
+  case AMDGPUIntrinsic::AMDGPU_fract:
+  case AMDGPUIntrinsic::AMDIL_fraction: // Legacy name.
+    return DAG.getNode(ISD::FSUB, DL, VT, Op.getOperand(1),
+                       DAG.getNode(ISD::FFLOOR, DL, VT, Op.getOperand(1)));
+
   default:
     return AMDGPUTargetLowering::LowerOperation(Op, DAG);
   }
diff --git a/llvm/lib/Target/R600/SIInstructions.td b/llvm/lib/Target/R600/SIInstructions.td
index 10a7aa30ecc..b06955c8331 100644
--- a/llvm/lib/Target/R600/SIInstructions.td
+++ b/llvm/lib/Target/R600/SIInstructions.td
@@ -3316,6 +3316,28 @@ def : Pat <
   (V_CNDMASK_B32_e64 $src0, $src1, $src2)
 >;
 
+//===----------------------------------------------------------------------===//
+// Fract Patterns
+//===----------------------------------------------------------------------===//
+
+let Predicates = [isCI] in {
+
+// Convert (x - floor(x)) to fract(x)
+def : Pat <
+  (f32 (fsub (f32 (VOP3Mods f32:$x, i32:$mods)),
+             (f32 (ffloor (f32 (VOP3Mods f32:$x, i32:$mods)))))),
+  (V_FRACT_F32_e64 $mods, $x, DSTCLAMP.NONE, DSTOMOD.NONE)
+>;
+
+// Convert (x + (-floor(x))) to fract(x)
+def : Pat <
+  (f64 (fadd (f64 (VOP3Mods f64:$x, i32:$mods)),
+             (f64 (fneg (f64 (ffloor (f64 (VOP3Mods f64:$x, i32:$mods)))))))),
+  (V_FRACT_F64_e64 $mods, $x, DSTCLAMP.NONE, DSTOMOD.NONE)
+>;
+
+} // End Predicates = [isCI]
+
 //============================================================================//
 // Miscellaneous Optimization Patterns
 //============================================================================//