maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity
llvm-project/llvm/test/Transforms/FunctionAttrs/optnone.ll

26 lines
574 B
LLVM
Raw Normal View History

[optnone] Make the optnone attribute effective at suppressing function attribute and function argument attribute synthesizing and propagating. As with the other uses of this attribute, the goal remains a best-effort (no guarantees) attempt to not optimize the function or assume things about the function when optimizing. This is particularly useful for compiler testing, bisecting miscompiles, triaging things, etc. I was hitting specific issues using optnone to isolate test code from a test driver for my fuzz testing, and this is one step of fixing that. llvm-svn: 215538
2014-08-13 18:49:33 +08:00
; RUN: opt < %s -functionattrs -S | FileCheck %s
[PM][FunctionAttrs] add NoUnwind attribute inference to PostOrderFunctionAttrs pass Summary: This was motivated by absence of PrunEH functionality in new PM. It was decided that a proper way to do PruneEH is to add NoUnwind inference into PostOrderFunctionAttrs and then perform normal SimplifyCFG on top. This change generalizes attribute handling implemented for (a removal of) Convergent attribute, by introducing a generic builder-like class AttributeInferer It registers all the attribute inference requests, storing per-attribute predicates into a vector, and then goes through an SCC Node, scanning all the instructions for not breaking attribute assumptions. The main idea is that as soon all the instructions from all the functions of SCC Node conform to attribute assumptions then we are free to infer the attribute as set for all the functions of SCC Node. It handles two distinct cases of attributes: - those that might break due to derefinement of the function code for these attributes we are allowed to apply inference only if all the functions are "exact definitions". Example - NoUnwind. - those that do not care about derefinement for these attributes we are allowed to apply inference as soon as we see any function definition. Example - removal of Convergent attribute. Also in this commit: * Converted all the FunctionAttrs tests to use FileCheck and added new-PM invocations to them * FunctionAttrs/convergent.ll test demonstrates a difference in behavior between new and old PM implementations. Marked with FIXME. * PruneEH tests were converted to new-PM as well, using function-attrs+simplify-cfg combo as intended * some of "other" tests were updated since function-attrs now infers 'nounwind' even for old PM pipeline * -disable-nounwind-inference hidden option added as a possible workaround for a supposedly rare case when nounwind being inferred by default presents a problem Reviewers: chandlerc, jlebar Reviewed By: jlebar Subscribers: eraman, llvm-commits Differential Revision: https://reviews.llvm.org/D44415 llvm-svn: 328377
2018-03-24 05:46:16 +08:00
; RUN: opt < %s -passes=function-attrs -S | FileCheck %s
[optnone] Make the optnone attribute effective at suppressing function attribute and function argument attribute synthesizing and propagating. As with the other uses of this attribute, the goal remains a best-effort (no guarantees) attempt to not optimize the function or assume things about the function when optimizing. This is particularly useful for compiler testing, bisecting miscompiles, triaging things, etc. I was hitting specific issues using optnone to isolate test code from a test driver for my fuzz testing, and this is one step of fixing that. llvm-svn: 215538
2014-08-13 18:49:33 +08:00
@x = global i32 0
define void @test_opt(i8* %p) {
; CHECK-LABEL: @test_opt
; CHECK: (i8* nocapture readnone %p) #0 {
ret void
}
define void @test_optnone(i8* %p) noinline optnone {
; CHECK-LABEL: @test_optnone
; CHECK: (i8* %p) #1 {
ret void
}
declare i8 @strlen(i8*) noinline optnone
; CHECK-LABEL: @strlen
[attrs] Move the norecurse deduction to operate on the node set rather than the SCC object, and have it scan the instruction stream directly rather than relying on call records. This makes the behavior of this routine consistent between libc routines and LLVM intrinsics for libc routines. We can go and start teaching it about those being norecurse, but we should behave the same for the intrinsic and the libc routine rather than differently. I chatted with James Molloy and the inconsistency doesn't seem intentional and likely is due to intrinsic calls not being modelled in the call graph analyses. This also fixes a bug where we would deduce norecurse on optnone functions, when generally we try to handle optnone functions as-if they were replaceable and thus unanalyzable. llvm-svn: 260813
2016-02-13 16:47:51 +08:00
; CHECK: (i8*) #1
[optnone] Make the optnone attribute effective at suppressing function attribute and function argument attribute synthesizing and propagating. As with the other uses of this attribute, the goal remains a best-effort (no guarantees) attempt to not optimize the function or assume things about the function when optimizing. This is particularly useful for compiler testing, bisecting miscompiles, triaging things, etc. I was hitting specific issues using optnone to isolate test code from a test driver for my fuzz testing, and this is one step of fixing that. llvm-svn: 215538
2014-08-13 18:49:33 +08:00
; CHECK-LABEL: attributes #0
[PM][FunctionAttrs] add NoUnwind attribute inference to PostOrderFunctionAttrs pass Summary: This was motivated by absence of PrunEH functionality in new PM. It was decided that a proper way to do PruneEH is to add NoUnwind inference into PostOrderFunctionAttrs and then perform normal SimplifyCFG on top. This change generalizes attribute handling implemented for (a removal of) Convergent attribute, by introducing a generic builder-like class AttributeInferer It registers all the attribute inference requests, storing per-attribute predicates into a vector, and then goes through an SCC Node, scanning all the instructions for not breaking attribute assumptions. The main idea is that as soon all the instructions from all the functions of SCC Node conform to attribute assumptions then we are free to infer the attribute as set for all the functions of SCC Node. It handles two distinct cases of attributes: - those that might break due to derefinement of the function code for these attributes we are allowed to apply inference only if all the functions are "exact definitions". Example - NoUnwind. - those that do not care about derefinement for these attributes we are allowed to apply inference as soon as we see any function definition. Example - removal of Convergent attribute. Also in this commit: * Converted all the FunctionAttrs tests to use FileCheck and added new-PM invocations to them * FunctionAttrs/convergent.ll test demonstrates a difference in behavior between new and old PM implementations. Marked with FIXME. * PruneEH tests were converted to new-PM as well, using function-attrs+simplify-cfg combo as intended * some of "other" tests were updated since function-attrs now infers 'nounwind' even for old PM pipeline * -disable-nounwind-inference hidden option added as a possible workaround for a supposedly rare case when nounwind being inferred by default presents a problem Reviewers: chandlerc, jlebar Reviewed By: jlebar Subscribers: eraman, llvm-commits Differential Revision: https://reviews.llvm.org/D44415 llvm-svn: 328377
2018-03-24 05:46:16 +08:00
; CHECK: = { norecurse nounwind readnone }
[optnone] Make the optnone attribute effective at suppressing function attribute and function argument attribute synthesizing and propagating. As with the other uses of this attribute, the goal remains a best-effort (no guarantees) attempt to not optimize the function or assume things about the function when optimizing. This is particularly useful for compiler testing, bisecting miscompiles, triaging things, etc. I was hitting specific issues using optnone to isolate test code from a test driver for my fuzz testing, and this is one step of fixing that. llvm-svn: 215538
2014-08-13 18:49:33 +08:00
; CHECK-LABEL: attributes #1
; CHECK: = { noinline optnone }