Commit Graph

4 Commits

Author SHA1 Message Date
Duncan P. N. Exon Smith be4d8cba1c Scalar: Remove remaining ilist iterator implicit conversions
Remove remaining `ilist_iterator` implicit conversions from
LLVMScalarOpts.

This change exposed some scary behaviour in
lib/Transforms/Scalar/SCCP.cpp around line 1770.  This patch changes a
call from `Function::begin()` to `&Function::front()`, since the return
was immediately being passed into another function that takes a
`Function*`.  `Function::front()` started to assert, since the function
was empty.  Note that `Function::end()` does not point at a legal
`Function*` -- it points at an `ilist_half_node` -- so the other
function was getting garbage before.  (I added the missing check for
`Function::isDeclaration()`.)

Otherwise, no functionality change intended.

llvm-svn: 250211
2015-10-13 19:26:58 +00:00
Jingyue Wu 5db9cba066 [Speculation] NFC: more header comments
explaining how it differs from SpeculativeExecuteBB in SimplifyCFG.

llvm-svn: 237724
2015-05-19 20:52:45 +00:00
Benjamin Kramer d9f06c8b87 Move Pass into anonymous namespace. NFC.
llvm-svn: 237526
2015-05-16 16:16:35 +00:00
Jingyue Wu 154eb5aa1d Add a speculative execution pass
Summary:
This is a pass for speculative execution of instructions for simple if-then (triangle) control flow. It's aimed at GPUs, but could perhaps be used in other contexts. Enabling this pass gives us a 1.0% geomean improvement on Google benchmark suites, with one benchmark improving 33%.

Credit goes to Jingyue Wu for writing an earlier version of this pass.

Patched by Bjarke Roune. 

Test Plan:
This patch adds a set of tests in test/Transforms/SpeculativeExecution/spec.ll
The pass is controlled by a flag which defaults to having the pass not run.

Reviewers: eliben, dberlin, meheff, jingyue, hfinkel

Reviewed By: jingyue, hfinkel

Subscribers: majnemer, jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D9360

llvm-svn: 237459
2015-05-15 17:54:48 +00:00