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llvm-project/llvm/test/CodeGen/AMDGPU/update-phi.ll

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Update phis in AMDGPUUnifyDivergentExitNodes Original patch https://reviews.llvm.org/D63659 from Steven Perron <stevenperron@google.com> The pass AMDGPUUnifyDivergentExitNodes does not update the phi nodes in the successors of blocks that is splits. This is fixed by calling BasicBlock::splitBasicBlock to split the block instead of doing it manually. This does extra work because a new conditional branch is created in BB which is immediately replaced, but I think the simplicity is worth it. It also helps make the code more future proof in case other things need to be updated. llvm-svn: 364342
2019-06-26 02:55:16 +08:00
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
[AMDGPU][SimplifyCFG] Teach AMDGPUUnifyDivergentExitNodes to preserve {,Post}DomTree This is a (last big?) part of the patch series to make SimplifyCFG preserve DomTree. Currently, it still does not actually preserve it, even thought it is pretty much fully updated to preserve it. Once the default is flipped, a valid DomTree must be passed into simplifyCFG, which means that whatever pass calls simplifyCFG, should also be smart about DomTree's. As far as i can see from `check-llvm` with default flipped, this is the last LLVM test batch (other than bugpoint tests) that needed fixes to not break with default flipped. The changes here are boringly identical to the ones i did over 42+ times/commits recently already, so while AMDGPU is outside of my normal ecosystem, i'm going to go for post-commit review here, like in all the other 42+ changes. Note that while the pass is taught to preserve {,Post}DomTree, it still doesn't do that by default, because simplifycfg still doesn't do that by default, and flipping default in this pass will implicitly flip the default for simplifycfg. That will happen, but not right now.
2021-01-02 04:18:35 +08:00
; RUN: opt -mtriple=amdgcn-- -S -amdgpu-unify-divergent-exit-nodes -verify -simplifycfg-require-and-preserve-domtree=1 %s | FileCheck -check-prefix=IR %s
Update phis in AMDGPUUnifyDivergentExitNodes Original patch https://reviews.llvm.org/D63659 from Steven Perron <stevenperron@google.com> The pass AMDGPUUnifyDivergentExitNodes does not update the phi nodes in the successors of blocks that is splits. This is fixed by calling BasicBlock::splitBasicBlock to split the block instead of doing it manually. This does extra work because a new conditional branch is created in BB which is immediately replaced, but I think the simplicity is worth it. It also helps make the code more future proof in case other things need to be updated. llvm-svn: 364342
2019-06-26 02:55:16 +08:00
; Make sure that the phi in n28 is updated when the block is split by unify
; divergent exit nodes.
define amdgpu_ps void @_amdgpu_ps_main() local_unnamed_addr #3 {
; IR-LABEL: @_amdgpu_ps_main(
; IR-NEXT: .entry:
; IR-NEXT: br label [[DOTLOOPEXIT:%.*]]
; IR: .loopexit:
; IR-NEXT: br label [[N28:%.*]]
; IR: n28:
; IR-NEXT: [[DOT01:%.*]] = phi float [ 0.000000e+00, [[DOTLOOPEXIT]] ], [ [[N29:%.*]], [[TRANSITIONBLOCK:%.*]] ]
; IR-NEXT: [[N29]] = fadd float [[DOT01]], 1.000000e+00
; IR-NEXT: [[N30:%.*]] = fcmp ogt float [[N29]], 4.000000e+00
AMDGPU: Fix AMDGPUUnifyDivergentExitNodes with no normal returns Summary: The code was assuming in a few places that if there was only one exit from the function that it was a normal return, which is invalid. It could be an infinite loop, in which case we still need to insert the usual fake edge so that the null export happens. This fixes shaders that end with an infinite loop that discards. Reviewers: arsenm, nhaehnle, critson Subscribers: kzhuravl, jvesely, wdng, yaxunl, dstuttard, tpr, t-tye, hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D71192
2019-12-09 19:04:00 +08:00
; IR-NEXT: br i1 true, label [[TRANSITIONBLOCK]], label [[UNIFIEDRETURNBLOCK:%.*]]
Update phis in AMDGPUUnifyDivergentExitNodes Original patch https://reviews.llvm.org/D63659 from Steven Perron <stevenperron@google.com> The pass AMDGPUUnifyDivergentExitNodes does not update the phi nodes in the successors of blocks that is splits. This is fixed by calling BasicBlock::splitBasicBlock to split the block instead of doing it manually. This does extra work because a new conditional branch is created in BB which is immediately replaced, but I think the simplicity is worth it. It also helps make the code more future proof in case other things need to be updated. llvm-svn: 364342
2019-06-26 02:55:16 +08:00
; IR: TransitionBlock:
; IR-NEXT: br i1 [[N30]], label [[DOTLOOPEXIT]], label [[N28]]
AMDGPU: Fix AMDGPUUnifyDivergentExitNodes with no normal returns Summary: The code was assuming in a few places that if there was only one exit from the function that it was a normal return, which is invalid. It could be an infinite loop, in which case we still need to insert the usual fake edge so that the null export happens. This fixes shaders that end with an infinite loop that discards. Reviewers: arsenm, nhaehnle, critson Subscribers: kzhuravl, jvesely, wdng, yaxunl, dstuttard, tpr, t-tye, hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D71192
2019-12-09 19:04:00 +08:00
; IR: UnifiedReturnBlock:
; IR-NEXT: call void @llvm.amdgcn.exp.f32(i32 9, i32 0, float undef, float undef, float undef, float undef, i1 true, i1 true)
Update phis in AMDGPUUnifyDivergentExitNodes Original patch https://reviews.llvm.org/D63659 from Steven Perron <stevenperron@google.com> The pass AMDGPUUnifyDivergentExitNodes does not update the phi nodes in the successors of blocks that is splits. This is fixed by calling BasicBlock::splitBasicBlock to split the block instead of doing it manually. This does extra work because a new conditional branch is created in BB which is immediately replaced, but I think the simplicity is worth it. It also helps make the code more future proof in case other things need to be updated. llvm-svn: 364342
2019-06-26 02:55:16 +08:00
; IR-NEXT: ret void
;
.entry:
br label %.loopexit
.loopexit: ; preds = %n28, %.entry
br label %n28
n28: ; preds = %.loopexit, %n28
%.01 = phi float [ 0.000000e+00, %.loopexit ], [ %n29, %n28 ]
%n29 = fadd float %.01, 1.0
%n30 = fcmp ogt float %n29, 4.000000e+00
br i1 %n30, label %.loopexit, label %n28
n31: ; preds =
ret void
}