[llvm] [AMDGPU] Marking super-reg as implicit-def in first spill instruction (PR #114773)

[Christudasan Devadasan via llvm-commits]

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@@ -0,0 +1,73 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -mtriple=amdgcn -mcpu=gfx908 %s -o - -run-pass prologepilog -verify-machineinstrs | FileCheck -check-prefix=GFX908 %s
+
+# During spill expansion, when VGPRs are available for spilling (stack is unused), tuple is being marked as
+# implicit-def as well as implicit in the first spill instrunction.
+
+---
+name:  agpr-spill-to-vgpr
+tracksRegLiveness: true
+stack:
+  - { id: 0, name: '', type: spill-slot, offset: 0, size: 128, alignment: 4 }
+machineFunctionInfo:
+  scratchRSrcReg:  $sgpr0_sgpr1_sgpr2_sgpr3
+  stackPtrOffsetReg: '$sgpr32'
+  hasSpilledVGPRs: true
+body: |
+  bb.0:
+    successors:
+    liveins: $vgpr0, $vgpr1
+
+    ; GFX908-LABEL: name: agpr-spill-to-vgpr
+    ; GFX908: liveins: $vgpr0, $vgpr1, $vgpr2, $vgpr3, $vgpr4, $vgpr5, $vgpr6, $vgpr7, $vgpr8, $vgpr9, $vgpr10, $vgpr11, $vgpr12, $vgpr13, $vgpr14, $vgpr15, $vgpr16, $vgpr17, $vgpr18, $vgpr19, $vgpr20, $vgpr21, $vgpr22, $vgpr23, $vgpr24, $vgpr25, $vgpr26, $vgpr27, $vgpr28, $vgpr29, $vgpr30, $vgpr31, $vgpr32, $vgpr33
+    ; GFX908-NEXT: {{  $}}
+    ; GFX908-NEXT: renamable $agpr0 = COPY renamable $vgpr0, implicit $exec
+    ; GFX908-NEXT: renamable $agpr2 = COPY renamable $vgpr1, implicit $exec
+    ; GFX908-NEXT: $vgpr33 = V_ACCVGPR_READ_B32_e64 $agpr0, implicit $exec, implicit-def $agpr0_agpr1_agpr2, implicit $agpr0_agpr1_agpr2
+    ; GFX908-NEXT: $vgpr32 = V_ACCVGPR_READ_B32_e64 $agpr1, implicit $exec
+    ; GFX908-NEXT: $vgpr31 = V_ACCVGPR_READ_B32_e64 $agpr2, implicit $exec, implicit $agpr0_agpr1_agpr2
+    ; GFX908-NEXT: S_ENDPGM 0
+    renamable $agpr0 = COPY renamable $vgpr0, implicit $exec
+    renamable $agpr2 = COPY renamable $vgpr1, implicit $exec
+    SI_SPILL_AV96_SAVE $agpr0_agpr1_agpr2, %stack.0, $sgpr32, 0, implicit $exec :: (store (s96) into %stack.0, align 4, addrspace 5)
+    S_ENDPGM 0
+...
+
+# During spill expansion, when VGPRs are NOT available for spilling (stack is used), tuple is being marked as
+# implicit-def ONLY and NOT implicit in the first spill instrunction.
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cdevadas wrote:

Pravin posted https://github.com/llvm/llvm-project/pull/115285 to handle it. But I guess we should add the implicit operand for all individual spills for the tuple, not just for the first and the last slices?

https://github.com/llvm/llvm-project/pull/114773