Changes in directory llvm/lib/Transforms/Scalar:
LoopStrengthReduce.cpp updated: 1.118 -> 1.119
---
Log message:
use types of loads and stores, not address, in CheckForIVReuse
---
Diffs of the changes: (+28 -7)
LoopStrengthReduce.cpp | 35 ++++++++++++++++++++++++++++-------
1 files changed, 28 insertions(+), 7 deletions(-)
Index: llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
diff -u llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp:1.118
llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp:1.119
--- llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp:1.118 Tue Mar 13
15:34:37 2007
+++ llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp Mon Mar 19 19:47:50 2007
@@ -43,6 +43,9 @@
STATISTIC(NumVariable, "Number of PHIs with variable strides");
namespace {
+
+ class BasedUser;
+
/// IVStrideUse - Keep track of one use of a strided induction variable,
where
/// the stride is stored externally. The Offset member keeps track of the
/// offset from the IV, User is the actual user of the operand, and 'Operand'
@@ -174,7 +177,10 @@
void OptimizeIndvars(Loop *L);
- unsigned CheckForIVReuse(const SCEVHandle&, IVExpr&, const Type*);
+ unsigned CheckForIVReuse(const SCEVHandle&, IVExpr&, const Type*,
+ const std::vector<BasedUser>& UsersToProcess);
+
+ bool ValidStride(int64_t, const std::vector<BasedUser>& UsersToProcess);
void StrengthReduceStridedIVUsers(const SCEVHandle &Stride,
IVUsersOfOneStride &Uses,
@@ -871,13 +877,25 @@
return false;
}
+/// ValidStride - Check whether the given Scale is valid for all loads and
+/// stores in UsersToProcess. Pulled into a function to avoid disturbing the
+/// sensibilities of those who dislike goto's.
+///
+bool LoopStrengthReduce::ValidStride(int64_t Scale,
+ const std::vector<BasedUser>& UsersToProcess) {
+ for (unsigned i=0, e = UsersToProcess.size(); i!=e; ++i)
+ if (!TLI->isLegalAddressScale(Scale, UsersToProcess[i].Inst->getType()))
+ return false;
+ return true;
+}
/// CheckForIVReuse - Returns the multiple if the stride is the multiple
/// of a previous stride and it is a legal value for the target addressing
/// mode scale component. This allows the users of this stride to be rewritten
/// as prev iv * factor. It returns 0 if no reuse is possible.
-unsigned LoopStrengthReduce::CheckForIVReuse(const SCEVHandle &Stride,
- IVExpr &IV, const Type *Ty) {
+unsigned LoopStrengthReduce::CheckForIVReuse(const SCEVHandle &Stride,
+ IVExpr &IV, const Type *Ty,
+ const std::vector<BasedUser>& UsersToProcess) {
if (!TLI) return 0;
if (SCEVConstant *SC = dyn_cast<SCEVConstant>(Stride)) {
@@ -890,7 +908,11 @@
if (unsigned(abs(SInt)) < SSInt || (SInt % SSInt) != 0)
continue;
int64_t Scale = SInt / SSInt;
- if (TLI->isLegalAddressScale(Scale, Ty)) {
+ // Check that this stride is valid for all the types used for loads and
+ // stores; if it can be used for some and not others, we might as well
use
+ // the original stride everywhere, since we have to create the IV for it
+ // anyway.
+ if (ValidStride(Scale, UsersToProcess))
for (std::vector<IVExpr>::iterator II = SI->second.IVs.begin(),
IE = SI->second.IVs.end(); II != IE; ++II)
// FIXME: Only handle base == 0 for now.
@@ -899,10 +921,8 @@
IV = *II;
return Scale;
}
- }
}
}
-
return 0;
}
@@ -955,7 +975,8 @@
Value *IncV = NULL;
IVExpr ReuseIV;
unsigned RewriteFactor = CheckForIVReuse(Stride, ReuseIV,
- CommonExprs->getType());
+ CommonExprs->getType(),
+ UsersToProcess);
if (RewriteFactor != 0) {
DOUT << "BASED ON IV of STRIDE " << *ReuseIV.Stride
<< " and BASE " << *ReuseIV.Base << " :\n";
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