From: Christian König <christian.koe...@amd.com>
Stop adding more instructions than necessary.
Signed-off-by: Christian König <christian.koe...@amd.com>
---
lib/Target/R600/AMDGPUStructurizeCFG.cpp | 40 +++++++++++++++++++++++++++++-
1 file changed, 39 insertions(+), 1 deletion(-)
diff --git a/lib/Target/R600/AMDGPUStructurizeCFG.cpp
b/lib/Target/R600/AMDGPUStructurizeCFG.cpp
index c2b084a..26f842e 100644
--- a/lib/Target/R600/AMDGPUStructurizeCFG.cpp
+++ b/lib/Target/R600/AMDGPUStructurizeCFG.cpp
@@ -22,8 +22,10 @@
#include "llvm/Analysis/RegionPass.h"
#include "llvm/IR/Module.h"
#include "llvm/Transforms/Utils/SSAUpdater.h"
+#include "llvm/Support/PatternMatch.h"
using namespace llvm;
+using namespace llvm::PatternMatch;
namespace {
@@ -193,6 +195,8 @@ class AMDGPUStructurizeCFG : public RegionPass {
void analyzeLoops(RegionNode *N);
+ Value *invert(Value *Condition);
+
Value *buildCondition(BranchInst *Term, unsigned Idx, bool Invert);
void gatherPredicates(RegionNode *N);
@@ -305,6 +309,40 @@ void AMDGPUStructurizeCFG::analyzeLoops(RegionNode *N) {
}
}
+/// \brief Invert the given condition
+Value *AMDGPUStructurizeCFG::invert(Value *Condition) {
+
+ // First: Check if it's a constant
+ if (Condition == BoolTrue)
+ return BoolFalse;
+
+ if (Condition == BoolFalse)
+ return BoolTrue;
+
+ if (Condition == BoolUndef)
+ return BoolUndef;
+
+ // Second: If the condition is already inverted, return the original value
+ if (match(Condition, m_Not(m_Value(Condition))))
+ return Condition;
+
+ // Third: Check all the users for an invert
+ BasicBlock *Parent = cast<Instruction>(Condition)->getParent();
+ for (Value::use_iterator I = Condition->use_begin(),
+ E = Condition->use_end(); I != E; ++I) {
+
+ Instruction *User = dyn_cast<Instruction>(*I);
+ if (!User || User->getParent() != Parent)
+ continue;
+
+ if (match(*I, m_Not(m_Specific(Condition))))
+ return *I;
+ }
+
+ // Last option: Create a new instruction
+ return BinaryOperator::CreateNot(Condition, "", Parent->getTerminator());
+}
+
/// \brief Build the condition for one edge
Value *AMDGPUStructurizeCFG::buildCondition(BranchInst *Term, unsigned Idx,
bool Invert) {
@@ -313,7 +351,7 @@ Value *AMDGPUStructurizeCFG::buildCondition(BranchInst
*Term, unsigned Idx,
Cond = Term->getCondition();
if (Idx != Invert)
- Cond = BinaryOperator::CreateNot(Cond, "", Term);
+ Cond = invert(Cond);
}
return Cond;
}
--
1.7.10.4
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