pull a bunch of logic out of instcombine into instsimplify for compare
simplification, this handles the foldable fcmp x,x cases among many others.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86627 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index c1f31f6..58a30d6 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -5941,26 +5941,14 @@
}
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-
- // Fold trivial predicates.
- if (I.getPredicate() == FCmpInst::FCMP_FALSE)
- return ReplaceInstUsesWith(I, ConstantInt::get(I.getType(), 0));
- if (I.getPredicate() == FCmpInst::FCMP_TRUE)
- return ReplaceInstUsesWith(I, ConstantInt::get(I.getType(), 1));
+ if (Value *V = SimplifyFCmpInst(I.getPredicate(), Op0, Op1, TD))
+ return ReplaceInstUsesWith(I, V);
+
// Simplify 'fcmp pred X, X'
if (Op0 == Op1) {
switch (I.getPredicate()) {
default: llvm_unreachable("Unknown predicate!");
- case FCmpInst::FCMP_UEQ: // True if unordered or equal
- case FCmpInst::FCMP_UGE: // True if unordered, greater than, or equal
- case FCmpInst::FCMP_ULE: // True if unordered, less than, or equal
- return ReplaceInstUsesWith(I, ConstantInt::get(I.getType(), 1));
- case FCmpInst::FCMP_OGT: // True if ordered and greater than
- case FCmpInst::FCMP_OLT: // True if ordered and less than
- case FCmpInst::FCMP_ONE: // True if ordered and operands are unequal
- return ReplaceInstUsesWith(I, ConstantInt::get(I.getType(), 0));
-
case FCmpInst::FCMP_UNO: // True if unordered: isnan(X) | isnan(Y)
case FCmpInst::FCMP_ULT: // True if unordered or less than
case FCmpInst::FCMP_UGT: // True if unordered or greater than
@@ -5981,23 +5969,8 @@
}
}
- if (isa<UndefValue>(Op1)) // fcmp pred X, undef -> undef
- return ReplaceInstUsesWith(I, UndefValue::get(I.getType()));
-
// Handle fcmp with constant RHS
if (Constant *RHSC = dyn_cast<Constant>(Op1)) {
- // If the constant is a nan, see if we can fold the comparison based on it.
- if (ConstantFP *CFP = dyn_cast<ConstantFP>(RHSC)) {
- if (CFP->getValueAPF().isNaN()) {
- if (FCmpInst::isOrdered(I.getPredicate())) // True if ordered and...
- return ReplaceInstUsesWith(I, ConstantInt::getFalse(*Context));
- assert(FCmpInst::isUnordered(I.getPredicate()) &&
- "Comparison must be either ordered or unordered!");
- // True if unordered.
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(*Context));
- }
- }
-
if (Instruction *LHSI = dyn_cast<Instruction>(Op0))
switch (LHSI->getOpcode()) {
case Instruction::PHI:
@@ -6055,24 +6028,11 @@
}
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
- const Type *Ty = Op0->getType();
-
- // icmp X, X
- if (Op0 == Op1)
- return ReplaceInstUsesWith(I, ConstantInt::get(I.getType(),
- I.isTrueWhenEqual()));
-
- if (isa<UndefValue>(Op1)) // X icmp undef -> undef
- return ReplaceInstUsesWith(I, UndefValue::get(I.getType()));
- // icmp <global/alloca*/null>, <global/alloca*/null> - Global/Stack value
- // addresses never equal each other! We already know that Op0 != Op1.
- if ((isa<GlobalValue>(Op0) || isa<AllocaInst>(Op0) ||
- isa<ConstantPointerNull>(Op0)) &&
- (isa<GlobalValue>(Op1) || isa<AllocaInst>(Op1) ||
- isa<ConstantPointerNull>(Op1)))
- return ReplaceInstUsesWith(I, ConstantInt::get(Type::getInt1Ty(*Context),
- !I.isTrueWhenEqual()));
+ if (Value *V = SimplifyICmpInst(I.getPredicate(), Op0, Op1, TD))
+ return ReplaceInstUsesWith(I, V);
+
+ const Type *Ty = Op0->getType();
// icmp's with boolean values can always be turned into bitwise operations
if (Ty == Type::getInt1Ty(*Context)) {
@@ -6137,27 +6097,24 @@
// If we have an icmp le or icmp ge instruction, turn it into the
// appropriate icmp lt or icmp gt instruction. This allows us to rely on
- // them being folded in the code below.
+ // them being folded in the code below. The SimplifyICmpInst code has
+ // already handled the edge cases for us, so we just assert on them.
switch (I.getPredicate()) {
default: break;
case ICmpInst::ICMP_ULE:
- if (CI->isMaxValue(false)) // A <=u MAX -> TRUE
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(*Context));
+ assert(!CI->isMaxValue(false)); // A <=u MAX -> TRUE
return new ICmpInst(ICmpInst::ICMP_ULT, Op0,
AddOne(CI));
case ICmpInst::ICMP_SLE:
- if (CI->isMaxValue(true)) // A <=s MAX -> TRUE
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(*Context));
+ assert(!CI->isMaxValue(true)); // A <=s MAX -> TRUE
return new ICmpInst(ICmpInst::ICMP_SLT, Op0,
AddOne(CI));
case ICmpInst::ICMP_UGE:
- if (CI->isMinValue(false)) // A >=u MIN -> TRUE
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(*Context));
+ assert(!CI->isMinValue(false)); // A >=u MIN -> TRUE
return new ICmpInst(ICmpInst::ICMP_UGT, Op0,
SubOne(CI));
case ICmpInst::ICMP_SGE:
- if (CI->isMinValue(true)) // A >=s MIN -> TRUE
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(*Context));
+ assert(!CI->isMinValue(true)); // A >=s MIN -> TRUE
return new ICmpInst(ICmpInst::ICMP_SGT, Op0,
SubOne(CI));
}