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author | Nicolai Haehnle <nhaehnle@gmail.com> | 2017-07-18 14:54:41 +0000 |
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committer | Nicolai Haehnle <nhaehnle@gmail.com> | 2017-07-18 14:54:41 +0000 |
commit | 78554e8137a116d34cc3c0cde8827864cf35f10b (patch) | |
tree | cf64e7e5508229195ea3a0e58f535a812abcc8c9 /test/CodeGen/MIR | |
parent | 7a0cfc0ffdd2e5c8064ade98eeded780158f5859 (diff) |
AMDGPU: Fix crash when folding immediates into multiple uses
Summary:
When an immediate is folded by constant folding, we re-scan the entire
use list for two reasons:
1. The constant folding may have created a new use of the same reg.
2. The constant folding may have removed an additional use in the list
we're currently traversing (e.g., constant folding an S_ADD_I32 c, c).
However, this could previously lead to a crash when an unrelated use was
added twice into the FoldList. Since we re-scan the whole list anyway, we
might as well just clear the FoldList again before we do so.
Using a MIR test to show this because real code seems to trigger the issue
only in connection with some really subtle control flow structures.
Fixes GL45-CTS.shading_language_420pack.binding_images on gfx9.
Reviewers: arsenm
Subscribers: kzhuravl, wdng, yaxunl, dstuttard, tpr, llvm-commits, t-tye
Differential Revision: https://reviews.llvm.org/D35416
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@308314 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/CodeGen/MIR')
-rw-r--r-- | test/CodeGen/MIR/AMDGPU/fold-multiple.mir | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/test/CodeGen/MIR/AMDGPU/fold-multiple.mir b/test/CodeGen/MIR/AMDGPU/fold-multiple.mir new file mode 100644 index 00000000000..a5da33a997d --- /dev/null +++ b/test/CodeGen/MIR/AMDGPU/fold-multiple.mir @@ -0,0 +1,40 @@ +# RUN: llc --mtriple=amdgcn--amdhsa -mcpu=fiji -verify-machineinstrs -run-pass si-fold-operands,si-shrink-instructions %s -o - | FileCheck %s +--- | + define amdgpu_kernel void @test() #0 { + ret void + } + + attributes #0 = { nounwind } + +... +--- + +# This used to crash / trigger an assertion, because re-scanning the use list +# after constant-folding the definition of %3 lead to the definition of %2 +# being processed twice. + +# CHECK-LABEL: name: test +# CHECK: %2 = V_LSHLREV_B32_e32 2, killed %0, implicit %exec +# CHECK: %4 = V_AND_B32_e32 8, killed %2, implicit %exec + +name: test +tracksRegLiveness: true +registers: + - { id: 0, class: vgpr_32 } + - { id: 1, class: sreg_32 } + - { id: 2, class: vgpr_32 } + - { id: 3, class: sreg_32 } + - { id: 4, class: vgpr_32 } + - { id: 5, class: sreg_128 } +body: | + bb.0 (%ir-block.0): + %0 = IMPLICIT_DEF + %1 = S_MOV_B32 2 + %2 = V_LSHLREV_B32_e64 %1, killed %0, implicit %exec + %3 = S_LSHL_B32 %1, killed %1, implicit-def dead %scc + %4 = V_AND_B32_e64 killed %2, killed %3, implicit %exec + %5 = IMPLICIT_DEF + BUFFER_STORE_DWORD_OFFSET killed %4, killed %5, 0, 0, 0, 0, 0, implicit %exec + S_ENDPGM + +... |