llvm/test/Transforms/SimplifyCFG, branch release_33

SimplifyCFG: If convert single conditional stores

2013-04-29T21:28:24Z

This resurrects r179957, but adds code that makes sure we don't touch atomic/volatile stores: This transformation will transform a conditional store with a preceeding uncondtional store to the same location: a[i] = may-alias with a[i] load if (cond) a[i] = Y into an unconditional store. a[i] = X may-alias with a[i] load tmp = cond ? Y : X; a[i] = tmp We assume that on average the cost of a mispredicted branch is going to be higher than the cost of a second store to the same location, and that the secondary benefits of creating a bigger basic block for other optimizations to work on outway the potential case where the branch would be correctly predicted and the cost of the executing the second store would be noticably reflected in performance. hmmer's execution time improves by 30% on an imac12,2 on ref data sets. With this change we are on par with gcc's performance (gcc also performs this transformation). There was a 1.2 % performance improvement on a ARM swift chip. Other tests in the test-suite+external seem to be mostly uninfluenced in my experiments: This optimization was triggered on 41 tests such that the executable was different before/after the patch. Only 1 out of the 40 tests (dealII) was reproducable below 100% (by about .4%). Given that hmmer benefits so much I believe this to be a fair trade off. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180731 91177308-0d34-0410-b5e6-96231b3b80d8

Revert "SimplifyCFG: If convert single conditional stores"

2013-04-21T13:09:04Z

There is the temptation to make this tranform dependent on target information as it is not going to be beneficial on all (sub)targets. Therefore, we should probably do this in MI Early-Ifconversion. This reverts commit r179957. Original commit message: "SimplifyCFG: If convert single conditional stores This transformation will transform a conditional store with a preceeding uncondtional store to the same location: a[i] = may-alias with a[i] load if (cond) a[i] = Y into an unconditional store. a[i] = X may-alias with a[i] load tmp = cond ? Y : X; a[i] = tmp We assume that on average the cost of a mispredicted branch is going to be higher than the cost of a second store to the same location, and that the secondary benefits of creating a bigger basic block for other optimizations to work on outway the potential case were the branch would be correctly predicted and the cost of the executing the second store would be noticably reflected in performance. hmmer's execution time improves by 30% on an imac12,2 on ref data sets. With this change we are on par with gcc's performance (gcc also performs this transformation). There was a 1.2 % performance improvement on a ARM swift chip. Other tests in the test-suite+external seem to be mostly uninfluenced in my experiments: This optimization was triggered on 41 tests such that the executable was different before/after the patch. Only 1 out of the 40 tests (dealII) was reproducable below 100% (by about .4%). Given that hmmer benefits so much I believe this to be a fair trade off. I am going to watch performance numbers across the builtbots and will revert this if anything unexpected comes up." git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179980 91177308-0d34-0410-b5e6-96231b3b80d8

SimplifyCFG: If convert single conditional stores

2013-04-20T21:42:09Z

This transformation will transform a conditional store with a preceeding uncondtional store to the same location: a[i] = may-alias with a[i] load if (cond) a[i] = Y into an unconditional store. a[i] = X may-alias with a[i] load tmp = cond ? Y : X; a[i] = tmp We assume that on average the cost of a mispredicted branch is going to be higher than the cost of a second store to the same location, and that the secondary benefits of creating a bigger basic block for other optimizations to work on outway the potential case were the branch would be correctly predicted and the cost of the executing the second store would be noticably reflected in performance. hmmer's execution time improves by 30% on an imac12,2 on ref data sets. With this change we are on par with gcc's performance (gcc also performs this transformation). There was a 1.2 % performance improvement on a ARM swift chip. Other tests in the test-suite+external seem to be mostly uninfluenced in my experiments: This optimization was triggered on 41 tests such that the executable was different before/after the patch. Only 1 out of the 40 tests (dealII) was reproducable below 100% (by about .4%). Given that hmmer benefits so much I believe this to be a fair trade off. I am going to watch performance numbers across the builtbots and will revert this if anything unexpected comes up. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179957 91177308-0d34-0410-b5e6-96231b3b80d8

simplifycfg: Fix integer overflow converting switch into icmp.

2013-04-16T08:35:36Z

If a switch instruction has a case for every possible value of its type, with the same successor, SimplifyCFG would replace it with an icmp ult, but the computation of the bound overflows in that case, which inverts the test. Patch by Jed Davis! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179587 91177308-0d34-0410-b5e6-96231b3b80d8

Converted 8x tests of SimplifyCFG to use FileCheck instead of grep.

2013-04-09T05:18:53Z

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179087 91177308-0d34-0410-b5e6-96231b3b80d8

Don't remove a landing pad if the invoke requires a table entry.

2013-03-11T20:53:00Z

An invoke may require a table entry. For instance, when the function it calls is expected to throw. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176827 91177308-0d34-0410-b5e6-96231b3b80d8

SimplifyCFG fix for volatile load/store.

2013-03-07T01:03:35Z

Fixes rdar:13349374. Volatile loads and stores need to be preserved even if the language standard says they are undefined. "volatile" in this context means "get out of the way compiler, let my platform handle it". Additionally, this is the only way I know of with llvm to write to the first page (when hardware allows) without dropping to assembly. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176599 91177308-0d34-0410-b5e6-96231b3b80d8

Use references to attribute groups on the call/invoke instructions.

2013-02-22T09:09:42Z

Listing all of the attributes for the callee of a call/invoke instruction is way too much and makes the IR unreadable. Use references to attributes instead. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175877 91177308-0d34-0410-b5e6-96231b3b80d8

Filecheckized 2x tests in SimplifyCFG and removed their date prefix to fit with current llvm style for test names.

2013-01-31T01:04:23Z

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174011 91177308-0d34-0410-b5e6-96231b3b80d8

Re-revert r173342, without losing the compile time improvements, flat

2013-01-27T06:42:03Z

out bug fixes, or functionality preserving refactorings. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173610 91177308-0d34-0410-b5e6-96231b3b80d8