[AMDGPU][LIT] Added a MIR LIT showing the SGPR spills #94584
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@llvm/pr-subscribers-backend-amdgpu Author: Vikash Gupta (vg0204) ChangesThis MIR test case is added to seek the consumption of VGPR lanes being used for SGPR spills during si-lower-sgpr-spills pass of AMDGPU pass pipeline. Basically, in this pass, stack slots are mapped to available VGPR lanes for spilling purpose, thus ending the need for stack slots. In current scenarion, each new SGPR spill goes into new VGPR lanes as, being mapped from its distinct stack slots assigned during SGPR allocation pass. It can be clearly seen in the added test case. Full diff: https://github.com/llvm/llvm-project/pull/94584.diff 1 Files Affected:
diff --git a/llvm/test/CodeGen/AMDGPU/si-lower-sgpr-spills-vgpr-lanes-usage.mir b/llvm/test/CodeGen/AMDGPU/si-lower-sgpr-spills-vgpr-lanes-usage.mir
new file mode 100644
index 00000000000000..a97d965d7e5ba0
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/si-lower-sgpr-spills-vgpr-lanes-usage.mir
@@ -0,0 +1,231 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 5
+# RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx908 -verify-machineinstrs -stress-regalloc=3 -start-before=greedy -stop-after=si-lower-sgpr-spills -o - %s | FileCheck -check-prefix=SGPR_SPILLED %s
+
+# This file contains 3 test cases to observe the optimal stack slot usage for SGPR spills utilizing Stack Slot Coloring pass.
+# @stack-slot-share-equal-sized-spills : In this, the stack slot indices is shared among the spill stack objects of equal size.
+# @stack-slot-share-unequal-sized-spills-with-large-spill-first AND
+# @stack-slot-share-unequal-sized-spills-with-small-spill-first :
+# In the remaining 2 test cases mentioned in just above 2 lines, the stack slot indices is shared among the spill stack objects of
+# unequal size, with spill slot having the size of the largest of the stack objects sharing the common stack indices.
+
+--- |
+ define void @stack-slot-share-equal-sized-spills(ptr addrspace(1) nocapture readnone %arg, ptr addrspace(1) noalias %arg1) {
+ bb:
+ %tmp = load i32, ptr addrspace(1) null, align 4
+ call void @func(i32 undef)
+ call void @func(i32 %tmp)
+ unreachable
+ }
+
+ define void @stack-slot-share-unequal-sized-spills-with-large-spill-first(ptr addrspace(1) nocapture readnone %arg, ptr addrspace(1) noalias %arg1) {
+ bb:
+ %tmp = load i32, ptr addrspace(1) null, align 4
+ call void @func(i32 undef)
+ call void @func(i32 %tmp)
+ unreachable
+ }
+
+ define void @stack-slot-share-unequal-sized-spills-with-small-spill-first(ptr addrspace(1) nocapture readnone %arg, ptr addrspace(1) noalias %arg1) {
+ bb:
+ %tmp = load i32, ptr addrspace(1) null, align 4
+ call void @func(i32 undef)
+ call void @func(i32 %tmp)
+ unreachable
+ }
+
+ declare void @func(i32)
+...
+
+---
+name: stack-slot-share-equal-sized-spills
+tracksRegLiveness: true
+frameInfo:
+ adjustsStack: true
+ hasCalls: true
+machineFunctionInfo:
+ scratchRSrcReg: $sgpr0_sgpr1_sgpr2_sgpr3
+ frameOffsetReg: $sgpr32
+ stackPtrOffsetReg: $sgpr32
+body: |
+ bb.0:
+ ; SGPR_SPILLED-LABEL: name: stack-slot-share-equal-sized-spills
+ ; SGPR_SPILLED: liveins: $sgpr30, $sgpr31, $vgpr62
+ ; SGPR_SPILLED-NEXT: {{ $}}
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
+ ; SGPR_SPILLED-NEXT: $vgpr62 = SI_SPILL_S32_TO_VGPR killed $sgpr30, 0, $vgpr62
+ ; SGPR_SPILLED-NEXT: $vgpr62 = SI_SPILL_S32_TO_VGPR killed $sgpr31, 1, $vgpr62
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = SI_SPILL_S32_TO_VGPR $sgpr32, 0, [[DEF]]
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = SI_SPILL_S32_TO_VGPR $sgpr0, 1, [[DEF]], implicit-def $sgpr0_sgpr1, implicit $sgpr0_sgpr1
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = SI_SPILL_S32_TO_VGPR $sgpr1, 2, [[DEF]], implicit $sgpr0_sgpr1
+ ; SGPR_SPILLED-NEXT: [[DEF1:%[0-9]+]]:vreg_64 = IMPLICIT_DEF
+ ; SGPR_SPILLED-NEXT: [[FLAT_LOAD_DWORD:%[0-9]+]]:vgpr_32 = FLAT_LOAD_DWORD [[DEF1]], 0, 0, implicit $exec, implicit $flat_scr
+ ; SGPR_SPILLED-NEXT: renamable $sgpr4_sgpr5 = SI_PC_ADD_REL_OFFSET target-flags(amdgpu-rel32-lo) @func + 4, target-flags(amdgpu-rel32-hi) @func + 4, implicit-def dead $scc
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = SI_SPILL_S32_TO_VGPR $sgpr4, 3, [[DEF]], implicit-def $sgpr4_sgpr5, implicit $sgpr4_sgpr5
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = SI_SPILL_S32_TO_VGPR killed $sgpr5, 4, [[DEF]], implicit killed $sgpr4_sgpr5
+ ; SGPR_SPILLED-NEXT: ADJCALLSTACKUP 0, 0, implicit-def $scc, implicit-def $sgpr32, implicit $sgpr32, implicit $sgpr32
+ ; SGPR_SPILLED-NEXT: $sgpr4 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 3, implicit-def $sgpr4_sgpr5
+ ; SGPR_SPILLED-NEXT: $sgpr5 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 4
+ ; SGPR_SPILLED-NEXT: dead $sgpr30_sgpr31 = SI_CALL killed renamable $sgpr4_sgpr5, @func, csr_amdgpu, implicit undef $vgpr0
+ ; SGPR_SPILLED-NEXT: $sgpr32 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 0
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = SI_SPILL_S32_TO_VGPR $sgpr32, 5, [[DEF]]
+ ; SGPR_SPILLED-NEXT: $sgpr0 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 1, implicit-def $sgpr0_sgpr1
+ ; SGPR_SPILLED-NEXT: $sgpr1 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 2
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = SI_SPILL_S32_TO_VGPR $sgpr2, 6, [[DEF]], implicit-def $sgpr2_sgpr3, implicit $sgpr2_sgpr3
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = SI_SPILL_S32_TO_VGPR $sgpr3, 7, [[DEF]], implicit $sgpr2_sgpr3
+ ; SGPR_SPILLED-NEXT: ADJCALLSTACKDOWN 0, 0, implicit-def $scc, implicit-def $sgpr32, implicit $sgpr32, implicit $sgpr32
+ ; SGPR_SPILLED-NEXT: ADJCALLSTACKUP 0, 0, implicit-def $scc, implicit-def $sgpr32, implicit $sgpr32, implicit $sgpr32
+ ; SGPR_SPILLED-NEXT: $vgpr0 = COPY [[FLAT_LOAD_DWORD]]
+ ; SGPR_SPILLED-NEXT: $sgpr4 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 3, implicit-def $sgpr4_sgpr5
+ ; SGPR_SPILLED-NEXT: $sgpr5 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 4
+ ; SGPR_SPILLED-NEXT: dead $sgpr30_sgpr31 = SI_CALL killed renamable $sgpr4_sgpr5, @func, csr_amdgpu, implicit killed $vgpr0
+ ; SGPR_SPILLED-NEXT: $sgpr32 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 5
+ ; SGPR_SPILLED-NEXT: $sgpr2 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 6, implicit-def $sgpr2_sgpr3
+ ; SGPR_SPILLED-NEXT: $sgpr3 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 7
+ ; SGPR_SPILLED-NEXT: ADJCALLSTACKDOWN 0, 0, implicit-def $scc, implicit-def $sgpr32, implicit $sgpr32, implicit $sgpr32
+ %0:sreg_32_xm0 = COPY $sgpr32
+ %5:sreg_64 = COPY $sgpr0_sgpr1
+ %1:vreg_64 = IMPLICIT_DEF
+ %2:vgpr_32 = FLAT_LOAD_DWORD %1, 0, 0, implicit $exec, implicit $flat_scr
+ %3:sreg_64 = SI_PC_ADD_REL_OFFSET target-flags(amdgpu-rel32-lo) @func + 4, target-flags(amdgpu-rel32-hi) @func + 4, implicit-def dead $scc
+ ADJCALLSTACKUP 0, 0, implicit-def $scc, implicit-def $sgpr32, implicit $sgpr32, implicit $sgpr32
+ dead $sgpr30_sgpr31 = SI_CALL %3, @func, csr_amdgpu, implicit undef $vgpr0
+ $sgpr32 = COPY %0
+ %4:sreg_32_xm0 = COPY $sgpr32
+ $sgpr0_sgpr1 = COPY %5
+ %6:sreg_64 = COPY $sgpr2_sgpr3
+ ADJCALLSTACKDOWN 0, 0, implicit-def $scc, implicit-def $sgpr32, implicit $sgpr32, implicit $sgpr32
+ ADJCALLSTACKUP 0, 0, implicit-def $scc, implicit-def $sgpr32, implicit $sgpr32, implicit $sgpr32
+ $vgpr0 = COPY %2
+ dead $sgpr30_sgpr31 = SI_CALL %3, @func, csr_amdgpu, implicit killed $vgpr0
+ $sgpr32 = COPY %4
+ $sgpr2_sgpr3 = COPY %6
+ ADJCALLSTACKDOWN 0, 0, implicit-def $scc, implicit-def $sgpr32, implicit $sgpr32, implicit $sgpr32
+...
+
+---
+name: stack-slot-share-unequal-sized-spills-with-large-spill-first
+tracksRegLiveness: true
+frameInfo:
+ adjustsStack: true
+ hasCalls: true
+machineFunctionInfo:
+ scratchRSrcReg: $sgpr0_sgpr1_sgpr2_sgpr3
+ frameOffsetReg: $sgpr32
+ stackPtrOffsetReg: $sgpr32
+body: |
+ bb.0:
+ ; SGPR_SPILLED-LABEL: name: stack-slot-share-unequal-sized-spills-with-large-spill-first
+ ; SGPR_SPILLED: liveins: $sgpr30, $sgpr31, $vgpr62
+ ; SGPR_SPILLED-NEXT: {{ $}}
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
+ ; SGPR_SPILLED-NEXT: $vgpr62 = SI_SPILL_S32_TO_VGPR killed $sgpr30, 0, $vgpr62
+ ; SGPR_SPILLED-NEXT: $vgpr62 = SI_SPILL_S32_TO_VGPR killed $sgpr31, 1, $vgpr62
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = SI_SPILL_S32_TO_VGPR $sgpr32, 0, [[DEF]]
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = SI_SPILL_S32_TO_VGPR $sgpr2, 1, [[DEF]], implicit-def $sgpr2_sgpr3, implicit $sgpr2_sgpr3
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = SI_SPILL_S32_TO_VGPR $sgpr3, 2, [[DEF]], implicit $sgpr2_sgpr3
+ ; SGPR_SPILLED-NEXT: [[DEF1:%[0-9]+]]:vreg_64 = IMPLICIT_DEF
+ ; SGPR_SPILLED-NEXT: [[FLAT_LOAD_DWORD:%[0-9]+]]:vgpr_32 = FLAT_LOAD_DWORD [[DEF1]], 0, 0, implicit $exec, implicit $flat_scr
+ ; SGPR_SPILLED-NEXT: renamable $sgpr4_sgpr5 = SI_PC_ADD_REL_OFFSET target-flags(amdgpu-rel32-lo) @func + 4, target-flags(amdgpu-rel32-hi) @func + 4, implicit-def dead $scc
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = SI_SPILL_S32_TO_VGPR $sgpr4, 3, [[DEF]], implicit-def $sgpr4_sgpr5, implicit $sgpr4_sgpr5
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = SI_SPILL_S32_TO_VGPR killed $sgpr5, 4, [[DEF]], implicit killed $sgpr4_sgpr5
+ ; SGPR_SPILLED-NEXT: ADJCALLSTACKUP 0, 0, implicit-def $scc, implicit-def $sgpr32, implicit $sgpr32, implicit $sgpr32
+ ; SGPR_SPILLED-NEXT: $sgpr4 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 3, implicit-def $sgpr4_sgpr5
+ ; SGPR_SPILLED-NEXT: $sgpr5 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 4
+ ; SGPR_SPILLED-NEXT: dead $sgpr30_sgpr31 = SI_CALL killed renamable $sgpr4_sgpr5, @func, csr_amdgpu, implicit undef $vgpr0
+ ; SGPR_SPILLED-NEXT: $sgpr32 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 0
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = SI_SPILL_S32_TO_VGPR $sgpr32, 5, [[DEF]]
+ ; SGPR_SPILLED-NEXT: $sgpr2 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 1, implicit-def $sgpr2_sgpr3
+ ; SGPR_SPILLED-NEXT: $sgpr3 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 2
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = SI_SPILL_S32_TO_VGPR $sgpr2, 6, [[DEF]]
+ ; SGPR_SPILLED-NEXT: ADJCALLSTACKDOWN 0, 0, implicit-def $scc, implicit-def $sgpr32, implicit $sgpr32, implicit $sgpr32
+ ; SGPR_SPILLED-NEXT: ADJCALLSTACKUP 0, 0, implicit-def $scc, implicit-def $sgpr32, implicit $sgpr32, implicit $sgpr32
+ ; SGPR_SPILLED-NEXT: $vgpr0 = COPY [[FLAT_LOAD_DWORD]]
+ ; SGPR_SPILLED-NEXT: $sgpr4 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 3, implicit-def $sgpr4_sgpr5
+ ; SGPR_SPILLED-NEXT: $sgpr5 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 4
+ ; SGPR_SPILLED-NEXT: dead $sgpr30_sgpr31 = SI_CALL killed renamable $sgpr4_sgpr5, @func, csr_amdgpu, implicit killed $vgpr0
+ ; SGPR_SPILLED-NEXT: $sgpr32 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 5
+ ; SGPR_SPILLED-NEXT: $sgpr2 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 6
+ ; SGPR_SPILLED-NEXT: ADJCALLSTACKDOWN 0, 0, implicit-def $scc, implicit-def $sgpr32, implicit $sgpr32, implicit $sgpr32
+ %0:sreg_32_xm0 = COPY $sgpr32
+ %5:sreg_64 = COPY $sgpr2_sgpr3
+ %1:vreg_64 = IMPLICIT_DEF
+ %2:vgpr_32 = FLAT_LOAD_DWORD %1, 0, 0, implicit $exec, implicit $flat_scr
+ %3:sreg_64 = SI_PC_ADD_REL_OFFSET target-flags(amdgpu-rel32-lo) @func + 4, target-flags(amdgpu-rel32-hi) @func + 4, implicit-def dead $scc
+ ADJCALLSTACKUP 0, 0, implicit-def $scc, implicit-def $sgpr32, implicit $sgpr32, implicit $sgpr32
+ dead $sgpr30_sgpr31 = SI_CALL %3, @func, csr_amdgpu, implicit undef $vgpr0
+ $sgpr32 = COPY %0
+ %4:sreg_32_xm0 = COPY $sgpr32
+ $sgpr2_sgpr3 = COPY %5
+ %6:sreg_32 = COPY $sgpr2
+ ADJCALLSTACKDOWN 0, 0, implicit-def $scc, implicit-def $sgpr32, implicit $sgpr32, implicit $sgpr32
+ ADJCALLSTACKUP 0, 0, implicit-def $scc, implicit-def $sgpr32, implicit $sgpr32, implicit $sgpr32
+ $vgpr0 = COPY %2
+ dead $sgpr30_sgpr31 = SI_CALL %3, @func, csr_amdgpu, implicit killed $vgpr0
+ $sgpr32 = COPY %4
+ $sgpr2 = COPY %6
+ ADJCALLSTACKDOWN 0, 0, implicit-def $scc, implicit-def $sgpr32, implicit $sgpr32, implicit $sgpr32
+...
+
+---
+name: stack-slot-share-unequal-sized-spills-with-small-spill-first
+tracksRegLiveness: true
+frameInfo:
+ adjustsStack: true
+ hasCalls: true
+machineFunctionInfo:
+ scratchRSrcReg: $sgpr0_sgpr1_sgpr2_sgpr3
+ frameOffsetReg: $sgpr32
+ stackPtrOffsetReg: $sgpr32
+body: |
+ bb.0:
+ ; SGPR_SPILLED-LABEL: name: stack-slot-share-unequal-sized-spills-with-small-spill-first
+ ; SGPR_SPILLED: liveins: $sgpr30, $sgpr31, $vgpr62
+ ; SGPR_SPILLED-NEXT: {{ $}}
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF
+ ; SGPR_SPILLED-NEXT: $vgpr62 = SI_SPILL_S32_TO_VGPR killed $sgpr30, 0, $vgpr62
+ ; SGPR_SPILLED-NEXT: $vgpr62 = SI_SPILL_S32_TO_VGPR killed $sgpr31, 1, $vgpr62
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = SI_SPILL_S32_TO_VGPR $sgpr32, 0, [[DEF]]
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = SI_SPILL_S32_TO_VGPR $sgpr0, 1, [[DEF]]
+ ; SGPR_SPILLED-NEXT: [[DEF1:%[0-9]+]]:vreg_64 = IMPLICIT_DEF
+ ; SGPR_SPILLED-NEXT: [[FLAT_LOAD_DWORD:%[0-9]+]]:vgpr_32 = FLAT_LOAD_DWORD [[DEF1]], 0, 0, implicit $exec, implicit $flat_scr
+ ; SGPR_SPILLED-NEXT: renamable $sgpr4_sgpr5 = SI_PC_ADD_REL_OFFSET target-flags(amdgpu-rel32-lo) @func + 4, target-flags(amdgpu-rel32-hi) @func + 4, implicit-def dead $scc
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = SI_SPILL_S32_TO_VGPR $sgpr4, 2, [[DEF]], implicit-def $sgpr4_sgpr5, implicit $sgpr4_sgpr5
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = SI_SPILL_S32_TO_VGPR killed $sgpr5, 3, [[DEF]], implicit killed $sgpr4_sgpr5
+ ; SGPR_SPILLED-NEXT: ADJCALLSTACKUP 0, 0, implicit-def $scc, implicit-def $sgpr32, implicit $sgpr32, implicit $sgpr32
+ ; SGPR_SPILLED-NEXT: $sgpr4 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 2, implicit-def $sgpr4_sgpr5
+ ; SGPR_SPILLED-NEXT: $sgpr5 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 3
+ ; SGPR_SPILLED-NEXT: dead $sgpr30_sgpr31 = SI_CALL killed renamable $sgpr4_sgpr5, @func, csr_amdgpu, implicit undef $vgpr0
+ ; SGPR_SPILLED-NEXT: $sgpr32 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 0
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = SI_SPILL_S32_TO_VGPR $sgpr32, 4, [[DEF]]
+ ; SGPR_SPILLED-NEXT: $sgpr0 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 1
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = SI_SPILL_S32_TO_VGPR $sgpr2, 5, [[DEF]], implicit-def $sgpr2_sgpr3, implicit $sgpr2_sgpr3
+ ; SGPR_SPILLED-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = SI_SPILL_S32_TO_VGPR $sgpr3, 6, [[DEF]], implicit $sgpr2_sgpr3
+ ; SGPR_SPILLED-NEXT: ADJCALLSTACKDOWN 0, 0, implicit-def $scc, implicit-def $sgpr32, implicit $sgpr32, implicit $sgpr32
+ ; SGPR_SPILLED-NEXT: ADJCALLSTACKUP 0, 0, implicit-def $scc, implicit-def $sgpr32, implicit $sgpr32, implicit $sgpr32
+ ; SGPR_SPILLED-NEXT: $vgpr0 = COPY [[FLAT_LOAD_DWORD]]
+ ; SGPR_SPILLED-NEXT: $sgpr4 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 2, implicit-def $sgpr4_sgpr5
+ ; SGPR_SPILLED-NEXT: $sgpr5 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 3
+ ; SGPR_SPILLED-NEXT: dead $sgpr30_sgpr31 = SI_CALL killed renamable $sgpr4_sgpr5, @func, csr_amdgpu, implicit killed $vgpr0
+ ; SGPR_SPILLED-NEXT: $sgpr32 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 4
+ ; SGPR_SPILLED-NEXT: $sgpr2 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 5, implicit-def $sgpr2_sgpr3
+ ; SGPR_SPILLED-NEXT: $sgpr3 = SI_RESTORE_S32_FROM_VGPR [[DEF]], 6
+ ; SGPR_SPILLED-NEXT: ADJCALLSTACKDOWN 0, 0, implicit-def $scc, implicit-def $sgpr32, implicit $sgpr32, implicit $sgpr32
+ %0:sreg_32_xm0 = COPY $sgpr32
+ %5:sreg_32 = COPY $sgpr0
+ %1:vreg_64 = IMPLICIT_DEF
+ %2:vgpr_32 = FLAT_LOAD_DWORD %1, 0, 0, implicit $exec, implicit $flat_scr
+ %3:sreg_64 = SI_PC_ADD_REL_OFFSET target-flags(amdgpu-rel32-lo) @func + 4, target-flags(amdgpu-rel32-hi) @func + 4, implicit-def dead $scc
+ ADJCALLSTACKUP 0, 0, implicit-def $scc, implicit-def $sgpr32, implicit $sgpr32, implicit $sgpr32
+ dead $sgpr30_sgpr31 = SI_CALL %3, @func, csr_amdgpu, implicit undef $vgpr0
+ $sgpr32 = COPY %0
+ %4:sreg_32_xm0 = COPY $sgpr32
+ $sgpr0 = COPY %5
+ %6:sreg_64 = COPY $sgpr2_sgpr3
+ ADJCALLSTACKDOWN 0, 0, implicit-def $scc, implicit-def $sgpr32, implicit $sgpr32, implicit $sgpr32
+ ADJCALLSTACKUP 0, 0, implicit-def $scc, implicit-def $sgpr32, implicit $sgpr32, implicit $sgpr32
+ $vgpr0 = COPY %2
+ dead $sgpr30_sgpr31 = SI_CALL %3, @func, csr_amdgpu, implicit killed $vgpr0
+ $sgpr32 = COPY %4
+ $sgpr2_sgpr3 = COPY %6
+ ADJCALLSTACKDOWN 0, 0, implicit-def $scc, implicit-def $sgpr32, implicit $sgpr32, implicit $sgpr32
+...
|
| # In the remaining 2 test cases mentioned in just above 2 lines, the stack slot indices is shared among the spill stack objects of | ||
| # unequal size, with spill slot having the size of the largest of the stack objects sharing the common stack indices. | ||
|
|
||
| --- | |
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You shouldn't need the IR section. The only thing the IR is providing you here is the required global callee for func, which you can substitute with a 0 in the MIR assuming the callee is insignificant (which it should be here)
| @@ -0,0 +1,231 @@ | |||
| # NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 5 | |||
| # RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx908 -verify-machineinstrs -stress-regalloc=3 -start-before=greedy -stop-after=si-lower-sgpr-spills -o - %s | FileCheck -check-prefix=SGPR_SPILLED %s | |||
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This test would be more reliable if it did not depend on register allocation behavior. Can you only run the post-RA passes?
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I did not understand much what you asked me to do, Can you elaborate more?
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Change the RUN line to use --start-before=stack-slot-coloring --stop-after=si-lower-sgpr-spills. The original test you have written should be modified first. To use this new RUN line, the test should be the output of sgpr-regalloc pipeline just before invoking the newly introduced stack slot coloring.
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Now, understood, thanks for the clarification!
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As I was trying to generate post optimized SGPR spills by adding " --start-before=stack-slot-coloring --stop-after=si-lower-sgpr-spills", I found that if stackSlotColoring(SSC) is introduced before SILowerSGPRSpills, it really depends on regAlloc. As StackSlotColoring pass uses LiveStack(LS) analysis results {which is currently computed at RegAlloc phase, as LS itself do not do anything}. So if we invoke SSC directly on 'input.mir' without LS results available, we actually won't see any stack slots optimization (in turn no sgpr spill optimization).
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There are multiple regalloc runs. The VGPR allocation should not matter here, so you should be able to start after it. You probably want -start-after=virtregrewriter,0
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The pipeline is stopped way before VGPR allocation here, as it happens much after SILowerSGPR spills. The -start-before=greedy, here it refers to SGPR greedy allocation, followed by virtRegRewriter & SILOwerSGPRSpill. I feel the change needed would either to use -sgpr-regalloc option OR use -start-before=greedy,0 to depict using SGPR allocation.
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Just like to add, VGPR allocation is happening after SGPR allocation already happened.
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@cdevadas, can you add your thoughts to it!
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I think it is reasonable to start the test from sgpr-regalloc and keep it until sgpr spill lowering to capture how the newly inserted stack slot coloring helps optimize vgpr lanes. I don't see any problem with the test.
| registers: | ||
| - { id: 0, class: sreg_32_xm0_xexec } | ||
| - { id: 1, class: sreg_64_xexec } | ||
| - { id: 2, class: vreg_64 } | ||
| - { id: 3, class: vgpr_32, preferred-register: '$vgpr0' } | ||
| - { id: 4, class: sreg_64 } | ||
| - { id: 5, class: sreg_32_xm0_xexec } | ||
| - { id: 6, class: sreg_64_xexec } | ||
| - { id: 7, class: sreg_64 } | ||
| - { id: 8, class: sreg_64 } | ||
| - { id: 9, class: sreg_64 } |
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Remove the registers section
| --- | ||
| name: stack-slot-share-equal-sized-spills | ||
| alignment: 1 |
| frameInfo: | ||
| maxAlignment: 4 |
| scratchRSrcReg: $sgpr0_sgpr1_sgpr2_sgpr3 | ||
| frameOffsetReg: $sgpr32 | ||
| stackPtrOffsetReg: $sgpr32 | ||
| maxKernArgAlign: 1 |
| argumentInfo: | ||
| privateSegmentBuffer: { reg: '$sgpr0_sgpr1_sgpr2_sgpr3' } | ||
| dispatchPtr: { reg: '$sgpr4_sgpr5' } | ||
| queuePtr: { reg: '$sgpr6_sgpr7' } | ||
| dispatchID: { reg: '$sgpr10_sgpr11' } | ||
| workGroupIDX: { reg: '$sgpr12' } | ||
| workGroupIDY: { reg: '$sgpr13' } | ||
| workGroupIDZ: { reg: '$sgpr14' } | ||
| LDSKernelId: { reg: '$sgpr15' } | ||
| implicitArgPtr: { reg: '$sgpr8_sgpr9' } | ||
| workItemIDX: { reg: '$vgpr31', mask: 1023 } | ||
| workItemIDY: { reg: '$vgpr31', mask: 1047552 } | ||
| workItemIDZ: { reg: '$vgpr31', mask: 1072693248 } |
| tracksRegLiveness: true | ||
| tracksDebugUserValues: true | ||
| registers: |
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Same in all these other functions, can remove most of this
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Wait for Matt if he has any concerns. |
| # NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 5 | ||
| # RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx908 -verify-machineinstrs -stress-regalloc=3 -start-before=greedy,0 -stop-after=si-lower-sgpr-spills -o - %s | FileCheck -check-prefix=SGPR_SPILLED %s | ||
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| # INFO : The pass pipeline is started from before the first iteration of register allocation pass that represents SGPR allocation in AMDGPU pipleine. |
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| # INFO : The pass pipeline is started from before the first iteration of register allocation pass that represents SGPR allocation in AMDGPU pipleine. | |
| # INFO : The test starts from the sgpr-regalloc pipeline. |
| # In the remaining 2 test cases mentioned in just above 2 lines, the stack slot indices is shared among the spill stack objects of | ||
| # unequal size, with spill slot having the size of the largest of the stack objects sharing the common stack indices. | ||
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@vg0204 Congratulations on having your first Pull Request (PR) merged into the LLVM Project! Your changes will be combined with recent changes from other authors, then tested Please check whether problems have been caused by your change specifically, as How to do this, and the rest of the post-merge process, is covered in detail here. If your change does cause a problem, it may be reverted, or you can revert it yourself. If you don't get any reports, no action is required from you. Your changes are working as expected, well done! |
This MIR test case is added to seek the consumption of VGPR lanes being used for SGPR spills during si-lower-sgpr-spills pass of AMDGPU pass pipeline. Basically, in this pass, stack slots are mapped to available VGPR lanes for spilling purpose, thus ending the need for stack slots. In current scenarion, each new SGPR spill goes into new VGPR lanes as, being mapped from its distinct stack slots assigned during SGPR allocation pass. It can be clearly seen in the added test case.
This test case is made to test post optimization SGPR spills which depends on StackSlotColoring pass which utilizes LiveStack analysis results. As for current scenarion LS analysis is really carried out at RA phase, making it necessary to be invoked in order for LS computation.
This MIR test case is added to seek the consumption of VGPR lanes being used for SGPR spills during si-lower-sgpr-spills pass of AMDGPU pass pipeline. Basically, in this pass, stack slots are mapped to available VGPR lanes for spilling purpose, thus ending the need for stack slots.
In current scenario, each new SGPR spill goes into new VGPR lanes as, being mapped from its distinct stack slots assigned during SGPR allocation pass. It can be clearly seen in the added test case.