SCEV fix: Handle loop invariant loads.

Fixes PR11882: NULL dereference in ComputeLoadConstantCompareExitLimit.

llvm-svn: 153480

switch SCEV to use the new ConstantFoldLoadThroughGEPIndices function
instead of its own hard coded thing, allowing it to handle
ConstantDataSequential and fixing some obscure bugs (e.g. it would
pr

switch SCEV to use the new ConstantFoldLoadThroughGEPIndices function
instead of its own hard coded thing, allowing it to handle
ConstantDataSequential and fixing some obscure bugs (e.g. it would
previously crash on a CAZ of vector type).

llvm-svn: 148788

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More dead code removal (using -Wunreachable-code)

llvm-svn: 148578

Remove obviously invalid early exit that prevented analyzing ConstantAggregateZeros.

Found by the clang static analyzer.

llvm-svn: 148540

Clarified the SCEV getSmallConstantTripCount interface with in-your-face comments.

This interface is misleading and dangerous, but it is actually what we need for unrolling.

llvm-svn: 147926

Expose isNonConstantNegative to users of ScalarEvolution.

llvm-svn: 147700

Fix a few more places where TargetData/TargetLibraryInfo is not being passed.
Add FIXMEs to places that are non-trivial to fix.

llvm-svn: 145661

Last bit of TargetLibraryInfo propagation. Also fixed a case for TargetData
where it appeared beneficial to pass.
More of rdar://10500969

llvm-svn: 145630

Propagate TargetLibraryInfo throughout ConstantFolding.cpp and
InstructionSimplify.cpp. Other fixups as needed.
Part of rdar://10500969

llvm-svn: 145559

SCEV fix. In general, Add/Mul expressions should not inherit NSW/NUW.

This reverts r139450, fixes r139453, and adds much needed comments and a
unit test.

llvm-svn: 145367

Make SCEV print <nsw><nuw> for Add/MulExpr.

llvm-svn: 145364

SCEV: Actually set overflow flags on add expressions.

setFlags doesn't modify its arguments.

llvm-svn: 145007

Fix SCEV overly optimistic back edge taken count for multi-exit loops.

Fixes PR11375: Different results for 'clang++ huh.cpp'...

llvm-svn: 144746

Don't try to loop on iterators that are potentially invalidated inside the loop. Fixes PR11361!

llvm-svn: 144454

Don't forget to check FlagNW when determining whether an AddRecExpr will wrap
or not. Patch by Brendon Cahoon!

llvm-svn: 144173

Restore commits 142790 and 142843 - they weren't breaking the build
bots. Original commit messages:
- Reapply r142781 with fix. Original message:

Enhance SCEV's brute force loop analysis to handl

Restore commits 142790 and 142843 - they weren't breaking the build
bots. Original commit messages:
- Reapply r142781 with fix. Original message:

Enhance SCEV's brute force loop analysis to handle multiple PHI nodes in the
loop header when computing the trip count.

With this, we now constant evaluate:
struct ListNode { const struct ListNode *next; int i; };
static const struct ListNode node1 = {0, 1};
static const struct ListNode node2 = {&node1, 2};
static const struct ListNode node3 = {&node2, 3};
int test() {
int sum = 0;
for (const struct ListNode *n = &node3; n != 0; n = n->next)
sum += n->i;
return sum;
}

- Now that we look at all the header PHIs, we need to consider all the header PHIs
when deciding that the loop has stopped evolving. Fixes miscompile in the gcc
torture testsuite!

llvm-svn: 142919

show more ...

Speculatively revert commits 142790 and 142843 to see if it fixes
the dragonegg and llvm-gcc self-host buildbots. Original commit
messages:
- Reapply r142781 with fix. Original message:

Enhance S

Speculatively revert commits 142790 and 142843 to see if it fixes
the dragonegg and llvm-gcc self-host buildbots. Original commit
messages:
- Reapply r142781 with fix. Original message:

Enhance SCEV's brute force loop analysis to handle multiple PHI nodes in the
loop header when computing the trip count.

With this, we now constant evaluate:
struct ListNode { const struct ListNode *next; int i; };
static const struct ListNode node1 = {0, 1};
static const struct ListNode node2 = {&node1, 2};
static const struct ListNode node3 = {&node2, 3};
int test() {
int sum = 0;
for (const struct ListNode *n = &node3; n != 0; n = n->next)
sum += n->i;
return sum;
}

- Now that we look at all the header PHIs, we need to consider all the header PHIs
when deciding that the loop has stopped evolving. Fixes miscompile in the gcc
torture testsuite!

llvm-svn: 142916

show more ...

Now that we look at all the header PHIs, we need to consider all the header PHIs
when deciding that the loop has stopped evolving. Fixes miscompile in the gcc
torture testsuite!

llvm-svn: 142843

Reapply r142781 with fix. Original message:

Enhance SCEV's brute force loop analysis to handle multiple PHI nodes in the
loop header when computing the trip count.

With this, we now constant

Reapply r142781 with fix. Original message:

Enhance SCEV's brute force loop analysis to handle multiple PHI nodes in the
loop header when computing the trip count.

With this, we now constant evaluate:
struct ListNode { const struct ListNode *next; int i; };
static const struct ListNode node1 = {0, 1};
static const struct ListNode node2 = {&node1, 2};
static const struct ListNode node3 = {&node2, 3};
int test() {
int sum = 0;
for (const struct ListNode *n = &node3; n != 0; n = n->next)
sum += n->i;
return sum;
}

llvm-svn: 142790

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PHI nodes not in the loop header aren't part of the loop iteration initial
state. Furthermore, they might not have two operands. This fixes the underlying
issue behind the crashes introduced in r1427

PHI nodes not in the loop header aren't part of the loop iteration initial
state. Furthermore, they might not have two operands. This fixes the underlying
issue behind the crashes introduced in r142781.

llvm-svn: 142788

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Speculatively revert r142781. Bots are showing
Assertion `i_nocapture < OperandTraits<PHINode>::operands(this) && "getOperand() out of range!"' failed.
coming out of indvars.

llvm-svn: 142786

Enhance SCEV's brute force loop analysis to handle multiple PHI nodes in the
loop header when computing the trip count.

With this, we now constant evaluate:
struct ListNode { const struct ListNode

Enhance SCEV's brute force loop analysis to handle multiple PHI nodes in the
loop header when computing the trip count.

With this, we now constant evaluate:
struct ListNode { const struct ListNode *next; int i; };
static const struct ListNode node1 = {0, 1};
static const struct ListNode node2 = {&node1, 2};
static const struct ListNode node3 = {&node2, 3};
int test() {
int sum = 0;
for (const struct ListNode *n = &node3; n != 0; n = n->next)
sum += n->i;
return sum;
}

llvm-svn: 142781

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Make SCEV's brute force analysis stronger in two ways. Firstly, we should be
able to constant fold load instructions where the argument is a constant.
Second, we should be able to watch multiple PHI

Make SCEV's brute force analysis stronger in two ways. Firstly, we should be
able to constant fold load instructions where the argument is a constant.
Second, we should be able to watch multiple PHI nodes through the loop; this
patch only supports PHIs in loop headers, more can be done here.

With this patch, we now constant evaluate:
static const int arr[] = {1, 2, 3, 4, 5};
int test() {
int sum = 0;
for (int i = 0; i < 5; ++i) sum += arr[i];
return sum;
}

llvm-svn: 142731

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An instruction's operands aren't necessarily instructions or constants. They
could be arguments, for example.

No testcase because this is a bug-fix broken out of a larger optimization patch.

llvm-s

An instruction's operands aren't necessarily instructions or constants. They
could be arguments, for example.

No testcase because this is a bug-fix broken out of a larger optimization patch.

llvm-svn: 141951

show more ...

Fixes PR11070 - assert in SCEV getConstantEvolvingPHIOperands.

llvm-svn: 141219