[llvm] [AMDGPU] Recover direct callees from called globals (PR #192199)

[Shilei Tian via llvm-commits]

================
@@ -0,0 +1,298 @@
+# RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 -start-after=prologepilog %s -o - | FileCheck %s
+
+--- |
+  ; ModuleID = '/tmp/amdgpu_called_global_regression.ll'
+  source_filename = "/tmp/amdgpu_called_global_regression.ll"
+  target datalayout = "e-m:e-p:64:64-p1:64:64-p2:32:32-p3:32:32-p4:64:64-p5:32:32-p6:32:32-p7:160:256:256:32-p8:128:128:128:48-p9:192:256:256:32-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024-v2048:2048-n32:64-S32-A5-G1-ni:7:8:9"
+  target triple = "amdgcn-amd-amdhsa"
+
+  define void @callee() #0 {
+  entry:
+    call void asm sideeffect "", "~{v0}"()
+    ret void
+  }
+
+  define void @caller() #0 {
+  entry:
+    call void @callee()
+    ret void
+  }
+
+  attributes #0 = { "target-cpu"="gfx900" }
+...
+---
+name:            callee
+alignment:       4
+exposesReturnsTwice: false
+legalized:       false
+regBankSelected: false
+selected:        false
+failedISel:      false
+tracksRegLiveness: true
+hasWinCFI:       false
+noPhis:          true
+isSSA:           false
+noVRegs:         true
+hasFakeUses:     false
+callsEHReturn:   false
+callsUnwindInit: false
+hasEHContTarget: false
+hasEHScopes:     false
+hasEHFunclets:   false
+isOutlined:      false
+debugInstrRef:   false
+failsVerification: false
+tracksDebugUserValues: true
+registers:       []
+liveins:         []
+frameInfo:
+  isFrameAddressTaken: false
+  isReturnAddressTaken: false
+  hasStackMap:     false
+  hasPatchPoint:   false
+  stackSize:       0
+  offsetAdjustment: 0
+  maxAlignment:    1
+  adjustsStack:    false
+  hasCalls:        false
+  stackProtector:  ''
+  functionContext: ''
+  maxCallFrameSize: 0
+  cvBytesOfCalleeSavedRegisters: 0
+  hasOpaqueSPAdjustment: false
+  hasVAStart:      false
+  hasMustTailInVarArgFunc: false
+  hasTailCall:     false
+  isCalleeSavedInfoValid: true
+  localFrameSize:  0
+fixedStack:      []
+stack:           []
+entry_values:    []
+callSites:       []
+debugValueSubstitutions: []
+constants:       []
+machineFunctionInfo:
+  explicitKernArgSize: 0
+  maxKernArgAlign: 1
+  ldsSize:         0
+  gdsSize:         0
+  dynLDSAlign:     1
+  isEntryFunction: false
+  isChainFunction: false
+  memoryBound:     false
+  waveLimiter:     false
+  hasSpilledSGPRs: false
+  hasSpilledVGPRs: false
+  numWaveDispatchSGPRs: 16
+  numWaveDispatchVGPRs: 0
+  scratchRSrcReg:  '$sgpr0_sgpr1_sgpr2_sgpr3'
+  frameOffsetReg:  '$sgpr33'
+  stackPtrOffsetReg: '$sgpr32'
+  bytesInStackArgArea: 0
+  returnsVoid:     true
+  argumentInfo:
+    privateSegmentBuffer: { reg: '$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 }
+  psInputAddr:     0
+  psInputEnable:   0
+  maxMemoryClusterDWords: 8
+  mode:
+    ieee:            true
+    dx10-clamp:      true
+    fp32-input-denormals: true
+    fp32-output-denormals: true
+    fp64-fp16-input-denormals: true
+    fp64-fp16-output-denormals: true
+  highBitsOf32BitAddress: 0
+  occupancy:       10
+  vgprForAGPRCopy: ''
+  sgprForEXECCopy: ''
+  longBranchReservedReg: ''
+  hasInitWholeWave: false
+  dynamicVGPRBlockSize: 0
+  scratchReservedForDynamicVGPRs: 0
+  numKernargPreloadSGPRs: 0
+  isWholeWaveFunction: false
+body:             |
+  ; CHECK-LABEL: {{^}}callee:
+  ; CHECK: .set callee.num_vgpr, 1
+  bb.0.entry:
+    INLINEASM &"", 1 /* sideeffect attdialect */, 12 /* clobber */, implicit-def dead early-clobber $vgpr0
+    SI_RETURN
+
+...
+---
+name:            caller
+alignment:       4
+exposesReturnsTwice: false
+legalized:       false
+regBankSelected: false
+selected:        false
+failedISel:      false
----------------
shiltian wrote:

most of these are not necessary. trim them down.

https://github.com/llvm/llvm-project/pull/192199