AMDGPU/SI: Select mad patterns to v_mac_f32

The two-address instruction pass will convert these back to v_mad_f32
if necessary.

Differential Revision: http://reviews.llvm.org/D11060

llvm-svn: 242038

1 files changed, 14 insertions, 2 deletions

diff --git a/llvm/lib/Target/AMDGPU/SIShrinkInstructions.cpp b/llvm/lib/Target/AMDGPU/SIShrinkInstructions.cpp
index cb9d7f7..e7511e6 100644
--- a/llvm/lib/Target/AMDGPU/SIShrinkInstructions.cpp
+++ b/llvm/lib/Target/AMDGPU/SIShrinkInstructions.cpp
@@ -94,8 +94,15 @@ static bool canShrink(MachineInstr &MI, const SIInstrInfo *TII,
   // is vcc.  We should handle this the same way we handle vopc, by addding
   // a register allocation hint pre-regalloc and then do the shrining
   // post-regalloc.
-  if (Src2)
-    return false;
+  if (Src2) {
+    if (MI.getOpcode() != AMDGPU::V_MAC_F32_e64)
+      return false;
+
+    const MachineOperand *Src2Mod =
+        TII->getNamedOperand(MI, AMDGPU::OpName::src2_modifiers);
+    if (!isVGPR(Src2, TRI, MRI) || (Src2Mod && Src2Mod->getImm() != 0))
+      return false;
+  }
 
   const MachineOperand *Src1 = TII->getNamedOperand(MI, AMDGPU::OpName::src1);
   const MachineOperand *Src1Mod =
@@ -259,6 +266,11 @@ bool SIShrinkInstructions::runOnMachineFunction(MachineFunction &MF) {
       if (Src1)
         Inst32.addOperand(*Src1);
 
+      const MachineOperand *Src2 =
+          TII->getNamedOperand(MI, AMDGPU::OpName::src2);
+      if (Src2)
+        Inst32.addOperand(*Src2);
+
       ++NumInstructionsShrunk;
       MI.eraseFromParent();