6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-06-23 01:24:30 +00:00
Code Issues Projects Releases Wiki Activity

PatternMatch: Introduce a matcher for instructions with the "exact" bit. Use it to simplify a few matchers.

Browse Source 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147403 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Benjamin Kramer
2012-01-01 17:55:30 +00:00
parent 395363a9b9
commit 55c6d57734
3 changed files with 30 additions and 19 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
lib/Analysis/ValueTracking.cpp
View File

@ -811,11 +811,9 @@ bool llvm::isPowerOfTwo(Value *V, const TargetData *TD, bool OrZero,
// An exact divide or right shift can only shift off zero bits, so the result
// is a power of two only if the first operand is a power of two and not
// copying a sign bit (sdiv int_min, 2).
if (match(V, m_LShr(m_Value(), m_Value())) ||
match(V, m_UDiv(m_Value(), m_Value()))) {
PossiblyExactOperator *PEO = cast<PossiblyExactOperator>(V);
if (PEO->isExact())
return isPowerOfTwo(PEO->getOperand(0), TD, OrZero, Depth);
if (match(V, m_Exact(m_LShr(m_Value(), m_Value()))) ||
match(V, m_Exact(m_UDiv(m_Value(), m_Value())))) {
return isPowerOfTwo(cast<Operator>(V)->getOperand(0), TD, OrZero, Depth);
}
return false;
@ -879,10 +877,8 @@ bool llvm::isKnownNonZero(Value *V, const TargetData *TD, unsigned Depth) {
return true;
}
// div exact can only produce a zero if the dividend is zero.
else if (match(V, m_IDiv(m_Value(X), m_Value()))) {
PossiblyExactOperator *BO = cast<PossiblyExactOperator>(V);
if (BO->isExact())
return isKnownNonZero(X, TD, Depth);
else if (match(V, m_Exact(m_IDiv(m_Value(X), m_Value())))) {
return isKnownNonZero(X, TD, Depth);
}
// X + Y.
else if (match(V, m_Add(m_Value(X), m_Value(Y)))) {