maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity
llvm-project/llvm/test/CodeGen/X86/break-anti-dependencies.ll

37 lines
1.3 KiB
LLVM
Raw Normal View History

Turn on list-ilp scheduling by default on x86 and x86-64, fix up testcases accordingly. Some are currently xfailed and will be filed as bugs to be fixed or understood. Performance results: roughly neutral on SPEC some micro benchmarks in the llvm suite are up between 100 and 150%, only a pair of regressions that are due to be investigated john-the-ripper saw: 10% improvement in traditional DES 8% improvement in BSDI DES 59% improvement in FreeBSD MD5 67% improvement in OpenBSD Blowfish 14% improvement in LM DES Small compile time impact. llvm-svn: 127208
2011-03-08 10:42:25 +08:00
; Without list-burr scheduling we may not see the difference in codegen here.
This patch fixes a problem which arose when using the Post-RA scheduler on X86 Atom. Some of our tests failed because the tail merging part of the BranchFolding pass was creating new basic blocks which did not contain live-in information. When the anti-dependency code in the Post-RA scheduler ran, it would sometimes rename the register containing the function return value because the fact that the return value was live-in to the subsequent block had been lost. To fix this, it is necessary to run the RegisterScavenging code in the BranchFolding pass. This patch makes sure that the register scavenging code is invoked in the X86 subtarget only when post-RA scheduling is being done. Post RA scheduling in the X86 subtarget is only done for Atom. This patch adds a new function to the TargetRegisterClass to control whether or not live-ins should be preserved during branch folding. This is necessary in order for the anti-dependency optimizations done during the PostRASchedulerList pass to work properly when doing Post-RA scheduling for the X86 in general and for the Intel Atom in particular. The patch adds and invokes the new function trackLivenessAfterRegAlloc() instead of using the existing requiresRegisterScavenging(). It changes BranchFolding.cpp to call trackLivenessAfterRegAlloc() instead of requiresRegisterScavenging(). It changes the all the targets that implemented requiresRegisterScavenging() to also implement trackLivenessAfterRegAlloc(). It adds an assertion in the Post RA scheduler to make sure that post RA liveness information is available when it is needed. It changes the X86 break-anti-dependencies test to use –mcpu=atom, in order to avoid running into the added assertion. Finally, this patch restores the use of anti-dependency checking (which was turned off temporarily for the 3.1 release) for Intel Atom in the Post RA scheduler. Patch by Andy Zhang! Thanks to Jakob and Anton for their reviews. llvm-svn: 155395
2012-04-24 05:39:35 +08:00
; Use a subtarget that has post-RA scheduling enabled because the anti-dependency
; breaker requires liveness information to be kept.
Enable MI Sched for x86. This changes the SelectionDAG scheduling preference to source order. Soon, the SelectionDAG scheduler can be bypassed saving a nice chunk of compile time. Performance differences that result from this change are often a consequence of register coalescing. The register coalescer is far from perfect. Bugs can be filed for deficiencies. On x86 SandyBridge/Haswell, the source order schedule is often preserved, particularly for small blocks. Register pressure is generally improved over the SD scheduler's ILP mode. However, we are still able to handle large blocks that require latency hiding, unlike the SD scheduler's BURR mode. MI scheduler also attempts to discover the critical path in single-block loops and adjust heuristics accordingly. The MI scheduler relies on the new machine model. This is currently unimplemented for AVX, so we may not be generating the best code yet. Unit tests are updated so they don't depend on SD scheduling heuristics. llvm-svn: 192750
2013-10-16 07:33:07 +08:00
; RUN: llc < %s -march=x86-64 -mcpu=atom -enable-misched=false -post-RA-scheduler -pre-RA-sched=list-burr -break-anti-dependencies=none > %t
Convert all tests using TCL-style quoting to use shell-style quoting. This was done through the aid of a terrible Perl creation. I will not paste any of the horrors here. Suffice to say, it require multiple staged rounds of replacements, state carried between, and a few nested-construct-parsing hacks that I'm not proud of. It happens, by luck, to be able to deal with all the TCL-quoting patterns in evidence in the LLVM test suite. If anyone is maintaining large out-of-tree test trees, feel free to poke me and I'll send you the steps I used to convert things, as well as answer any painful questions etc. IRC works best for this type of thing I find. Once converted, switch the LLVM lit config to use ShTests the same as Clang. In addition to being able to delete large amounts of Python code from 'lit', this will also simplify the entire test suite and some of lit's architecture. Finally, the test suite runs 33% faster on Linux now. ;] For my 16-hardware-thread (2x 4-core xeon e5520): 36s -> 24s llvm-svn: 159525
2012-07-02 20:47:22 +08:00
; RUN: grep "%xmm0" %t | count 14
; RUN: not grep "%xmm1" %t
This patch fixes a problem which arose when using the Post-RA scheduler on X86 Atom. Some of our tests failed because the tail merging part of the BranchFolding pass was creating new basic blocks which did not contain live-in information. When the anti-dependency code in the Post-RA scheduler ran, it would sometimes rename the register containing the function return value because the fact that the return value was live-in to the subsequent block had been lost. To fix this, it is necessary to run the RegisterScavenging code in the BranchFolding pass. This patch makes sure that the register scavenging code is invoked in the X86 subtarget only when post-RA scheduling is being done. Post RA scheduling in the X86 subtarget is only done for Atom. This patch adds a new function to the TargetRegisterClass to control whether or not live-ins should be preserved during branch folding. This is necessary in order for the anti-dependency optimizations done during the PostRASchedulerList pass to work properly when doing Post-RA scheduling for the X86 in general and for the Intel Atom in particular. The patch adds and invokes the new function trackLivenessAfterRegAlloc() instead of using the existing requiresRegisterScavenging(). It changes BranchFolding.cpp to call trackLivenessAfterRegAlloc() instead of requiresRegisterScavenging(). It changes the all the targets that implemented requiresRegisterScavenging() to also implement trackLivenessAfterRegAlloc(). It adds an assertion in the Post RA scheduler to make sure that post RA liveness information is available when it is needed. It changes the X86 break-anti-dependencies test to use –mcpu=atom, in order to avoid running into the added assertion. Finally, this patch restores the use of anti-dependency checking (which was turned off temporarily for the 3.1 release) for Intel Atom in the Post RA scheduler. Patch by Andy Zhang! Thanks to Jakob and Anton for their reviews. llvm-svn: 155395
2012-04-24 05:39:35 +08:00
; RUN: llc < %s -march=x86-64 -mcpu=atom -post-RA-scheduler -break-anti-dependencies=critical > %t
Convert all tests using TCL-style quoting to use shell-style quoting. This was done through the aid of a terrible Perl creation. I will not paste any of the horrors here. Suffice to say, it require multiple staged rounds of replacements, state carried between, and a few nested-construct-parsing hacks that I'm not proud of. It happens, by luck, to be able to deal with all the TCL-quoting patterns in evidence in the LLVM test suite. If anyone is maintaining large out-of-tree test trees, feel free to poke me and I'll send you the steps I used to convert things, as well as answer any painful questions etc. IRC works best for this type of thing I find. Once converted, switch the LLVM lit config to use ShTests the same as Clang. In addition to being able to delete large amounts of Python code from 'lit', this will also simplify the entire test suite and some of lit's architecture. Finally, the test suite runs 33% faster on Linux now. ;] For my 16-hardware-thread (2x 4-core xeon e5520): 36s -> 24s llvm-svn: 159525
2012-07-02 20:47:22 +08:00
; RUN: grep "%xmm0" %t | count 7
; RUN: grep "%xmm1" %t | count 7
Restore the -post-RA-scheduler flag as an override for the target specification. Remove -mattr for setting PostRAScheduler enable and instead use CPU string. llvm-svn: 83215
2009-10-02 05:46:35 +08:00
define void @goo(double* %r, double* %p, double* %q) nounwind {
entry:
[opaque pointer type] Add textual IR support for explicit type parameter to load instruction Essentially the same as the GEP change in r230786. A similar migration script can be used to update test cases, though a few more test case improvements/changes were required this time around: (r229269-r229278) import fileinput import sys import re pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)") for line in sys.stdin: sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line)) Reviewers: rafael, dexonsmith, grosser Differential Revision: http://reviews.llvm.org/D7649 llvm-svn: 230794
2015-02-28 05:17:42 +08:00
%0 = load double, double* %p, align 8
Restore the -post-RA-scheduler flag as an override for the target specification. Remove -mattr for setting PostRAScheduler enable and instead use CPU string. llvm-svn: 83215
2009-10-02 05:46:35 +08:00
%1 = fadd double %0, 1.100000e+00
%2 = fmul double %1, 1.200000e+00
%3 = fadd double %2, 1.300000e+00
%4 = fmul double %3, 1.400000e+00
%5 = fadd double %4, 1.500000e+00
%6 = fptosi double %5 to i32
[opaque pointer type] Add textual IR support for explicit type parameter to load instruction Essentially the same as the GEP change in r230786. A similar migration script can be used to update test cases, though a few more test case improvements/changes were required this time around: (r229269-r229278) import fileinput import sys import re pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)") for line in sys.stdin: sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line)) Reviewers: rafael, dexonsmith, grosser Differential Revision: http://reviews.llvm.org/D7649 llvm-svn: 230794
2015-02-28 05:17:42 +08:00
%7 = load double, double* %r, align 8
Restore the -post-RA-scheduler flag as an override for the target specification. Remove -mattr for setting PostRAScheduler enable and instead use CPU string. llvm-svn: 83215
2009-10-02 05:46:35 +08:00
%8 = fadd double %7, 7.100000e+00
%9 = fmul double %8, 7.200000e+00
%10 = fadd double %9, 7.300000e+00
%11 = fmul double %10, 7.400000e+00
%12 = fadd double %11, 7.500000e+00
%13 = fptosi double %12 to i32
%14 = icmp slt i32 %6, %13
br i1 %14, label %bb, label %return
bb:
store double 9.300000e+00, double* %q, align 8
ret void
return:
ret void
}