[llvm] r235671 - R600/SI: Special case v_mov_b32 as really rematerializable

[Matt Arsenault]

Author: arsenm
Date: Thu Apr 23 18:34:48 2015
New Revision: 235671

URL: http://llvm.org/viewvc/llvm-project?rev=235671&view=rev
Log:
R600/SI: Special case v_mov_b32 as really rematerializable

This should be fixed to properly understand all rematerializable
instructions while ignoring implicit reads of exec.

Modified:
    llvm/trunk/lib/Target/R600/SIInstrInfo.cpp
    llvm/trunk/lib/Target/R600/SIInstrInfo.h

Modified: llvm/trunk/lib/Target/R600/SIInstrInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/R600/SIInstrInfo.cpp?rev=235671&r1=235670&r2=235671&view=diff
==============================================================================
--- llvm/trunk/lib/Target/R600/SIInstrInfo.cpp (original)
+++ llvm/trunk/lib/Target/R600/SIInstrInfo.cpp Thu Apr 23 18:34:48 2015
@@ -74,6 +74,20 @@ static bool nodesHaveSameOperandValue(SD
   return N0->getOperand(Op0Idx) == N1->getOperand(Op1Idx);
 }
 
+bool SIInstrInfo::isReallyTriviallyReMaterializable(const MachineInstr *MI,
+                                                    AliasAnalysis *AA) const {
+  // TODO: The generic check fails for VALU instructions that should be
+  // rematerializable due to implicit reads of exec. We really want all of the
+  // generic logic for this except for this.
+  switch (MI->getOpcode()) {
+  case AMDGPU::V_MOV_B32_e32:
+  case AMDGPU::V_MOV_B32_e64:
+    return true;
+  default:
+    return false;
+  }
+}
+
 bool SIInstrInfo::areLoadsFromSameBasePtr(SDNode *Load0, SDNode *Load1,
                                           int64_t &Offset0,
                                           int64_t &Offset1) const {

Modified: llvm/trunk/lib/Target/R600/SIInstrInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/R600/SIInstrInfo.h?rev=235671&r1=235670&r2=235671&view=diff
==============================================================================
--- llvm/trunk/lib/Target/R600/SIInstrInfo.h (original)
+++ llvm/trunk/lib/Target/R600/SIInstrInfo.h Thu Apr 23 18:34:48 2015
@@ -72,6 +72,9 @@ public:
     return RI;
   }
 
+  bool isReallyTriviallyReMaterializable(const MachineInstr *MI,
+                                         AliasAnalysis *AA) const override;
+
   bool areLoadsFromSameBasePtr(SDNode *Load1, SDNode *Load2,
                                int64_t &Offset1,
                                int64_t &Offset2) const override;