[AMDGPU][GlobalISel] Add RegBankLegalize support for G_READSTEADYCOUNTER (#163661)

Author: vangthao95

llvm/lib/Target/AMDGPU/AMDGPURegBankLegalizeRules.cpp

@@ -901,6 +901,8 @@ RegBankLegalizeRules::RegBankLegalizeRules(const GCNSubtarget &_ST,
 
   addRulesForGOpcs({G_ABS}, Standard).Uni(S16, {{Sgpr32Trunc}, {Sgpr32SExt}});
 
+  addRulesForGOpcs({G_READSTEADYCOUNTER}, Standard).Uni(S64, {{Sgpr64}, {}});
+
   bool hasSALUFloat = ST->hasSALUFloatInsts();
 
   addRulesForGOpcs({G_FADD}, Standard)

llvm/test/CodeGen/AMDGPU/readsteadycounter.ll

@@ -1,8 +1,8 @@
 ; RUN: llc -global-isel=0 -mtriple=amdgcn -mcpu=gfx700 < %s | FileCheck %s -check-prefixes=GCN,GFX700
 ; RUN: llc -global-isel=0 -mtriple=amdgcn -mcpu=gfx900 < %s | FileCheck %s -check-prefixes=GCN,GFX900
-; RUN: llc -global-isel=1 -mtriple=amdgcn -mcpu=gfx900 < %s | FileCheck %s -check-prefixes=GCN,GFX900
+; RUN: llc -global-isel=1 -new-reg-bank-select -mtriple=amdgcn -mcpu=gfx900 < %s | FileCheck %s -check-prefixes=GCN,GFX900
 ; RUN: llc -global-isel=0 -mtriple=amdgcn -mcpu=gfx1100 < %s | FileCheck %s -check-prefixes=GCN,GFX1100
-; RUN: llc -global-isel=1 -mtriple=amdgcn -mcpu=gfx1100 < %s | FileCheck %s -check-prefixes=GCN,GFX1100
+; RUN: llc -global-isel=1 -new-reg-bank-select -mtriple=amdgcn -mcpu=gfx1100 < %s | FileCheck %s -check-prefixes=GCN,GFX1100
 
 declare i64 @llvm.readsteadycounter() #0