AMDGPU/GlobalISel: Add selectVOP3Mods_nnan

This doesn't enable any new imports yet, but moves the fmed patterns
from failing on this to hitting the "complex suboperand referenced
more than once" limitation in tablegen.

3 files changed, 20 insertions, 0 deletions

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUGISel.td b/llvm/lib/Target/AMDGPU/AMDGPUGISel.td
index b198bfb0e41..9b62e54da2b 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUGISel.td
+++ b/llvm/lib/Target/AMDGPU/AMDGPUGISel.td
@@ -30,6 +30,10 @@ def gi_vop3mods :
     GIComplexOperandMatcher<s32, "selectVOP3Mods">,
     GIComplexPatternEquiv<VOP3Mods>;
 
+def gi_vop3mods_nnan :
+    GIComplexOperandMatcher<s32, "selectVOP3Mods_nnan">,
+    GIComplexPatternEquiv<VOP3Mods_nnan>;
+
 def gi_vop3omods :
     GIComplexOperandMatcher<s32, "selectVOP3OMods">,
     GIComplexPatternEquiv<VOP3OMods>;
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp b/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp
index 876c7c35294..c0830ac2a0b 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp
@@ -1771,6 +1771,20 @@ AMDGPUInstructionSelector::selectVOP3Mods(MachineOperand &Root) const {
 }
 
 InstructionSelector::ComplexRendererFns
+AMDGPUInstructionSelector::selectVOP3Mods_nnan(MachineOperand &Root) const {
+  Register Src;
+  unsigned Mods;
+  std::tie(Src, Mods) = selectVOP3ModsImpl(Root.getReg());
+  if (!TM.Options.NoNaNsFPMath && !isKnownNeverNaN(Src, *MRI))
+    return None;
+
+  return {{
+      [=](MachineInstrBuilder &MIB) { MIB.addReg(Src); },
+      [=](MachineInstrBuilder &MIB) { MIB.addImm(Mods); }  // src_mods
+  }};
+}
+
+InstructionSelector::ComplexRendererFns
 AMDGPUInstructionSelector::selectVOP3OpSelMods0(MachineOperand &Root) const {
   // FIXME: Handle clamp and op_sel
   return {{
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.h b/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.h
index 1de8a0abbc1..c249c7e44e6 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.h
+++ b/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.h
@@ -132,6 +132,8 @@ private:
   selectVOP3OMods(MachineOperand &Root) const;
   InstructionSelector::ComplexRendererFns
   selectVOP3Mods(MachineOperand &Root) const;
+  InstructionSelector::ComplexRendererFns
+  selectVOP3Mods_nnan(MachineOperand &Root) const;
 
   InstructionSelector::ComplexRendererFns
   selectVOP3OpSelMods0(MachineOperand &Root) const;