Commit Graph

13 Commits

Author SHA1 Message Date
Dan Gohman 45774ce0ad Reapply the new LoopStrengthReduction code, with compile time and
bug fixes, and with improved heuristics for analyzing foreign-loop
addrecs.

This change also flattens IVUsers, eliminating the stride-oriented
groupings, which makes it easier to work with.

llvm-svn: 95975
2010-02-12 10:34:29 +00:00
Dan Gohman 045f81981a Revert LoopStrengthReduce.cpp to pre-r94061 for now.
llvm-svn: 94123
2010-01-22 00:46:49 +00:00
Dan Gohman 51ad99d2c5 Re-implement the main strength-reduction portion of LoopStrengthReduction.
This new version is much more aggressive about doing "full" reduction in
cases where it reduces register pressure, and also more aggressive about
rewriting induction variables to count down (or up) to zero when doing so
reduces register pressure.

It currently uses fairly simplistic algorithms for finding reuse
opportunities, but it introduces a new framework allows it to combine
multiple strategies at once to form hybrid solutions, instead of doing
all full-reduction or all base+index.

llvm-svn: 94061
2010-01-21 02:09:26 +00:00
Evan Cheng f42b5af549 Re-apply 85799. It turns out my code isn't buggy.
llvm-svn: 85947
2009-11-03 21:40:02 +00:00
Evan Cheng a8a58efc03 Revert 85799 for now. It might be breaking llvm-gcc driver.
llvm-svn: 85827
2009-11-02 21:49:14 +00:00
Evan Cheng 2729543984 Initilize the machine LICM CSE map upon the first time an instruction is hoisted to
the loop preheader. Add instructions which are already in the preheader block that
may be common expressions of those that are hoisted out. These does get a few more
instructions CSE'ed.

llvm-svn: 85799
2009-11-02 08:09:49 +00:00
Dan Gohman 40503396da Eliminate more uses of llvm-as and llvm-dis.
llvm-svn: 81290
2009-09-08 23:54:48 +00:00
Dan Gohman a5b9645c4b Split the Add, Sub, and Mul instruction opcodes into separate
integer and floating-point opcodes, introducing
FAdd, FSub, and FMul.

For now, the AsmParser, BitcodeReader, and IRBuilder all preserve
backwards compatability, and the Core LLVM APIs preserve backwards
compatibility for IR producers. Most front-ends won't need to change
immediately.

This implements the first step of the plan outlined here:
http://nondot.org/sabre/LLVMNotes/IntegerOverflow.txt

llvm-svn: 72897
2009-06-04 22:49:04 +00:00
Dale Johannesen 02cb2bf2e3 Reverse a loop that is counting up to a maximum to
count down to 0 instead, under very restricted
circumstances.  Adjust 4 testcases in which this
optimization fires.

llvm-svn: 71439
2009-05-11 17:15:42 +00:00
Owen Anderson 31a0dea5c0 Eliminate another use of -disable-correct-folding.
llvm-svn: 54356
2008-08-05 18:03:01 +00:00
Owen Anderson 5018bd032a Update these tests to work by disabling the new correct CFG generation. This flag should ONLY be used to for tests like these.
llvm-svn: 54334
2008-08-04 23:55:29 +00:00
Evan Cheng 73db52ebf8 Enable two-address remat by default.
llvm-svn: 52701
2008-06-25 01:16:38 +00:00
Evan Cheng b10dc27b20 Do not fold reload into an instruction with multiple uses. It issues one extra load.
llvm-svn: 44467
2007-11-30 21:23:43 +00:00