to find opportunities for store-to-load forwarding or load CSE,
in the same way that visitStore scans back to do DSE. Also, define
a new helper function for testing whether the addresses of two
memory accesses are known to have the same value, and use it in
both visitStore and visitLoad.

These two changes allow instcombine to eliminate loads in code
produced by front-ends that frequently emit obviously redundant
addressing for memory references.

llvm-svn: 57608

llvm-svn: 57515

- Renumber fcmp predicates to match their icmp counterparts.
- Try swapping operands to expose more optimization opportunities.

llvm-svn: 57513

     ord && olt -> olt
     ord && ueq -> oeq

llvm-svn: 57507

constant expression with all zero indices as being the same as a bitcast.

llvm-svn: 57442

a couple other cases for clarity, but shouldn't affect correctness.

Patch by Eli Friedman!

llvm-svn: 57387

This patch fixes PR 2869

llvm-svn: 57369

llvm-svn: 57353

and APFloat::convertToInteger.  Restore return value to
IEEE754.  Adjust all users accordingly.

llvm-svn: 57329

Patch by Samuel Tardieu.

llvm-svn: 57291

patch by Samuel Tardieu!

llvm-svn: 57288

llvm-svn: 57221

This includes not marking a GEP involving a vector as unsafe, but only when it
has all zero indices. This allows scalarrepl to work in a few more cases.

llvm-svn: 57177

shifting and masking inside a bswap expr.  This allows it to handle
the cases from PR2842, which involve the intermediate 'or' 
expressions being shifted, not just the input value.

llvm-svn: 57095

ashr.  It should only apply to lshr.

llvm-svn: 57089

pointer bitcasts and GEP's", and centralize the
logic in Value::getUnderlyingObject.  The
difference with stripPointerCasts is that
stripPointerCasts only strips GEPs if all
indices are zero, while getUnderlyingObject
strips GEPs no matter what the indices are.

llvm-svn: 56922

instruction, not after. This fixes some uses of free'd memory.

llvm-svn: 56908

llvm-svn: 56834

llvm-svn: 56716

- return attributes - inreg, zext and sext
- parameter attributes
- function attributes - nounwind, readonly, readnone, noreturn

Return attributes use 0 as the index.
Function attributes use ~0U as the index.

This patch requires corresponding changes in llvm-gcc and clang.

llvm-svn: 56704

s/ParamAttr/Attribute/g
s/PAList/AttrList/g
s/FnAttributeWithIndex/AttributeWithIndex/g
s/FnAttr/Attribute/g

This sets the stage 
- to implement function notes as function attributes and 
- to distinguish between function attributes and return value attributes.

This requires corresponding changes in llvm-gcc and clang.

llvm-svn: 56622

llvm-svn: 56549

llvm-svn: 56546

llvm-svn: 56535

llvm-svn: 56527

Do not check isDeclaration() in hasNote(). It is clients' responsibility.

llvm-svn: 56524

llvm-svn: 56513

Function Notes also. Function notes are stored at index ~0.

llvm-svn: 56511

llvm-svn: 56477

llvm-svn: 56419

Unfortunately this means removing one regression test
of GlobalsModRef because I couldn't work out how to
perform it without MarkModRef.

llvm-svn: 56342

Fixes PR 2805

llvm-svn: 56321

Thanks to Ji Young Park for the patch!

llvm-svn: 56316

This one slipped through cracks very well.

llvm-svn: 56284

 - Recognize expressions like "x > -1 ? x : 0" as min/max and turn them
   into expressions like "x < 0 ? 0 : x", which is easily recognizable
   as a min/max operation.
 - Refrain from folding expression like "y/2 < 1" to "y < 2" when the
   comparison is being used as part of a min or max idiom, like
   "y/2 < 1 ? 1 : y/2". In that case, the division has another use, so
   folding doesn't eliminate it, and obfuscates the min/max, making it
   harder to recognize as a min/max operation.

These benefit ScalarEvolution, CodeGen, and anything else that wants to
recognize integer min and max.

llvm-svn: 56246

cases.  See the comment above OptimizeSMax for the full story, and
the testcase for an example. This cancels out a pessimization
commonly attributed to indvars, and will allow us to lift some of
the artificial throttles in indvars, rather than add new ones.

llvm-svn: 56230

getelementptr indices, inserting an explicit cast if necessary.
This helps expose the sign-extension operation to other optimizations.

llvm-svn: 56133

Patch by Nicolas Capens!

llvm-svn: 56129

cases it was still getting lucky and detecting overflow
but it was clearly incorrect.

llvm-svn: 56113

multiplication overflows.

llvm-svn: 56082