AMDGPU: Do basic folding of class intrinsic
This allows more of the OCML builtin library to be
constant folded.
llvm-svn: 280586
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index 00fdc46..ca868f0 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -2237,6 +2237,85 @@
break;
}
+ case Intrinsic::amdgcn_class: {
+ enum {
+ S_NAN = 1 << 0, // Signaling NaN
+ Q_NAN = 1 << 1, // Quiet NaN
+ N_INFINITY = 1 << 2, // Negative infinity
+ N_NORMAL = 1 << 3, // Negative normal
+ N_SUBNORMAL = 1 << 4, // Negative subnormal
+ N_ZERO = 1 << 5, // Negative zero
+ P_ZERO = 1 << 6, // Positive zero
+ P_SUBNORMAL = 1 << 7, // Positive subnormal
+ P_NORMAL = 1 << 8, // Positive normal
+ P_INFINITY = 1 << 9 // Positive infinity
+ };
+
+ const uint32_t FullMask = S_NAN | Q_NAN | N_INFINITY | N_NORMAL |
+ N_SUBNORMAL | N_ZERO | P_ZERO | P_SUBNORMAL | P_NORMAL | P_INFINITY;
+
+ Value *Src0 = II->getArgOperand(0);
+ Value *Src1 = II->getArgOperand(1);
+ const ConstantInt *CMask = dyn_cast<ConstantInt>(Src1);
+ if (!CMask) {
+ if (isa<UndefValue>(Src0))
+ return replaceInstUsesWith(*II, UndefValue::get(II->getType()));
+
+ if (isa<UndefValue>(Src1))
+ return replaceInstUsesWith(*II, ConstantInt::get(II->getType(), false));
+ break;
+ }
+
+ uint32_t Mask = CMask->getZExtValue();
+
+ // If all tests are made, it doesn't matter what the value is.
+ if ((Mask & FullMask) == FullMask)
+ return replaceInstUsesWith(*II, ConstantInt::get(II->getType(), true));
+
+ if ((Mask & FullMask) == 0)
+ return replaceInstUsesWith(*II, ConstantInt::get(II->getType(), false));
+
+ if (Mask == (S_NAN | Q_NAN)) {
+ // Equivalent of isnan. Replace with standard fcmp.
+ Value *FCmp = Builder->CreateFCmpUNO(Src0, Src0);
+ FCmp->takeName(II);
+ return replaceInstUsesWith(*II, FCmp);
+ }
+
+ const ConstantFP *CVal = dyn_cast<ConstantFP>(Src0);
+ if (!CVal) {
+ if (isa<UndefValue>(Src0))
+ return replaceInstUsesWith(*II, UndefValue::get(II->getType()));
+
+ // Clamp mask to used bits
+ if ((Mask & FullMask) != Mask) {
+ CallInst *NewCall = Builder->CreateCall(II->getCalledFunction(),
+ { Src0, ConstantInt::get(Src1->getType(), Mask & FullMask) }
+ );
+
+ NewCall->takeName(II);
+ return replaceInstUsesWith(*II, NewCall);
+ }
+
+ break;
+ }
+
+ const APFloat &Val = CVal->getValueAPF();
+
+ bool Result =
+ ((Mask & S_NAN) && Val.isNaN() && Val.isSignaling()) ||
+ ((Mask & Q_NAN) && Val.isNaN() && !Val.isSignaling()) ||
+ ((Mask & N_INFINITY) && Val.isInfinity() && Val.isNegative()) ||
+ ((Mask & N_NORMAL) && Val.isNormal() && Val.isNegative()) ||
+ ((Mask & N_SUBNORMAL) && Val.isDenormal() && Val.isNegative()) ||
+ ((Mask & N_ZERO) && Val.isZero() && Val.isNegative()) ||
+ ((Mask & P_ZERO) && Val.isZero() && !Val.isNegative()) ||
+ ((Mask & P_SUBNORMAL) && Val.isDenormal() && !Val.isNegative()) ||
+ ((Mask & P_NORMAL) && Val.isNormal() && !Val.isNegative()) ||
+ ((Mask & P_INFINITY) && Val.isInfinity() && !Val.isNegative());
+
+ return replaceInstUsesWith(*II, ConstantInt::get(II->getType(), Result));
+ }
case Intrinsic::stackrestore: {
// If the save is right next to the restore, remove the restore. This can
// happen when variable allocas are DCE'd.