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| author | Austin Kerbow <Austin.Kerbow@amd.com> | 2019-10-28 09:39:20 -0700 |
|---|---|---|
| committer | Austin Kerbow <Austin.Kerbow@amd.com> | 2019-10-28 10:02:22 -0700 |
| commit | d11b93ec6ac1cf48dce0a8b7beb3e07f0ee9b0fc (patch) | |
| tree | 3f5a885b61fe23680e336adfccf92a09a6303c19 /llvm/test/CodeGen/AMDGPU | |
| parent | 2ddd1564a9c2c648ac63fcaca474d5386cebd3fe (diff) | |
| download | bcm5719-llvm-d11b93ec6ac1cf48dce0a8b7beb3e07f0ee9b0fc.tar.gz bcm5719-llvm-d11b93ec6ac1cf48dce0a8b7beb3e07f0ee9b0fc.zip | |
AMDGPU: Avoid overwriting saved PC
Summary:
An outstanding load with same destination sgpr as call could cause PC to be
updated with junk value on return.
Reviewers: arsenm, rampitec
Reviewed By: arsenm
Subscribers: kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D69474
Diffstat (limited to 'llvm/test/CodeGen/AMDGPU')
| -rw-r--r-- | llvm/test/CodeGen/AMDGPU/call-waw-waitcnt.mir | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/llvm/test/CodeGen/AMDGPU/call-waw-waitcnt.mir b/llvm/test/CodeGen/AMDGPU/call-waw-waitcnt.mir new file mode 100644 index 00000000000..e3021cfe096 --- /dev/null +++ b/llvm/test/CodeGen/AMDGPU/call-waw-waitcnt.mir @@ -0,0 +1,53 @@ +# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py +# RUN: llc -march=amdgcn -mcpu=gfx900 -verify-machineinstrs -run-pass=si-insert-waitcnts %s -o - | FileCheck -check-prefix=GCN %s + +# $sgpr30_sgpr31 will hold the return address. We need a waitcnt before SI_CALL so +# that the return address is not clobbered in the callee by the outstanding load. + +--- | + define amdgpu_kernel void @call_waw_waitcnt() #0 { + %1 = call i32 @func() + ret void + } + + declare hidden i32 @func() #0 + + attributes #0 = { nounwind } +... + +--- +name: call_waw_waitcnt +tracksRegLiveness: true +body: | + bb.0: + liveins: $sgpr4_sgpr5, $sgpr7, $sgpr0_sgpr1_sgpr2_sgpr3 + + ; GCN-LABEL: name: call_waw_waitcnt + ; GCN: liveins: $sgpr4_sgpr5, $sgpr7, $sgpr0_sgpr1_sgpr2_sgpr3 + ; GCN: S_WAITCNT 0 + ; GCN: $sgpr30_sgpr31 = S_LOAD_DWORDX2_IMM $sgpr4_sgpr5, 0, 0, 0 + ; GCN: $sgpr33 = S_MOV_B32 killed $sgpr7 + ; GCN: $flat_scr_lo = S_ADD_U32 killed $sgpr4, $sgpr33, implicit-def $scc + ; GCN: $flat_scr_hi = S_ADDC_U32 killed $sgpr5, 0, implicit-def $scc, implicit killed $scc + ; GCN: BUNDLE implicit-def $sgpr4_sgpr5, implicit-def $sgpr4, implicit-def $sgpr5, implicit-def $scc { + ; GCN: $sgpr4_sgpr5 = S_GETPC_B64 + ; GCN: $sgpr4 = S_ADD_U32 internal $sgpr4, target-flags(amdgpu-rel32-lo) @func + 4, implicit-def $scc + ; GCN: $sgpr5 = S_ADDC_U32 internal $sgpr5, target-flags(amdgpu-rel32-hi) @func + 4, implicit-def $scc, implicit internal $scc + ; GCN: } + ; GCN: $sgpr32 = S_MOV_B32 $sgpr33 + ; GCN: S_WAITCNT 49279 + ; GCN: dead $sgpr30_sgpr31 = SI_CALL killed renamable $sgpr4_sgpr5, @func, csr_amdgpu_highregs, implicit $sgpr0_sgpr1_sgpr2_sgpr3, implicit-def dead $vgpr0 + ; GCN: S_ENDPGM 0 + $sgpr30_sgpr31 = S_LOAD_DWORDX2_IMM $sgpr4_sgpr5, 0, 0, 0 + $sgpr33 = S_MOV_B32 killed $sgpr7 + $flat_scr_lo = S_ADD_U32 killed $sgpr4, $sgpr33, implicit-def $scc + $flat_scr_hi = S_ADDC_U32 killed $sgpr5, 0, implicit-def $scc, implicit killed $scc + BUNDLE implicit-def $sgpr4_sgpr5, implicit-def $sgpr4, implicit-def $sgpr5, implicit-def $scc { + $sgpr4_sgpr5 = S_GETPC_B64 + $sgpr4 = S_ADD_U32 internal $sgpr4, target-flags(amdgpu-rel32-lo) @func + 4, implicit-def $scc + $sgpr5 = S_ADDC_U32 internal $sgpr5, target-flags(amdgpu-rel32-hi) @func + 4, implicit-def $scc, implicit internal $scc + } + $sgpr32 = S_MOV_B32 $sgpr33 + dead $sgpr30_sgpr31 = SI_CALL killed renamable $sgpr4_sgpr5, @func, csr_amdgpu_highregs, implicit $sgpr0_sgpr1_sgpr2_sgpr3, implicit-def dead $vgpr0 + S_ENDPGM 0 +... |
