MIR: Freeze reserved regs after parsing everything

The AMDGPU implementation of getReservedRegs depends on
MachineFunctionInfo fields that are parsed from the YAML section. This
was reserving the wrong register since it was setting the reserved
regs before parsing the correct one.

Some tests were relying on the default reserved set for the assumed
default calling convention.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357083 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/MIRParser/MIRParser.cpp

@@ -426,6 +426,14 @@ MIRParserImpl::initializeMachineFunction(const yaml::MachineFunction &YamlMF,
     }
   }
 
+  // Set the reserved registers after parsing MachineFuncInfo. The target may
+  // have been recording information used to select the reserved registers
+  // there.
+  // FIXME: This is a temporary workaround until the reserved registers can be
+  // serialized.
+  MachineRegisterInfo &MRI = MF.getRegInfo();
+  MRI.freezeReservedRegs(MF);
+
   computeFunctionProperties(MF);
 
   MF.getSubtarget().mirFileLoaded(MF);
@@ -564,9 +572,6 @@ bool MIRParserImpl::setupRegisterInfo(const PerFunctionMIParsingState &PFS,
     }
   }
 
-  // FIXME: This is a temporary workaround until the reserved registers can be
-  // serialized.
-  MRI.freezeReservedRegs(MF);
   return Error;
 }
 

test/CodeGen/AMDGPU/GlobalISel/regbankselect-phi.mir

@@ -1075,7 +1075,7 @@ body: |
   ; CHECK:   liveins: $vgpr0, $vgpr1, $sgpr0
   ; CHECK:   [[COPY:%[0-9]+]]:vgpr(s32) = COPY $vgpr0
   ; CHECK:   [[COPY1:%[0-9]+]]:vgpr(s32) = COPY $vgpr1
-  ; CHECK:   [[COPY2:%[0-9]+]]:sgpr(s32) = COPY $sgpr1
+  ; CHECK:   [[COPY2:%[0-9]+]]:sgpr(s32) = COPY $sgpr0
   ; CHECK:   [[C:%[0-9]+]]:sgpr(s32) = G_CONSTANT i32 0
   ; CHECK:   [[TRUNC:%[0-9]+]]:vgpr(s1) = G_TRUNC [[COPY]](s32)
   ; CHECK:   [[ICMP:%[0-9]+]]:scc(s1) = G_ICMP intpred(eq), [[COPY2]](s32), [[C]]
@@ -1097,7 +1097,7 @@ body: |
 
     %0:_(s32) = COPY $vgpr0
     %1:_(s32) = COPY $vgpr1
-    %2:_(s32) = COPY $sgpr1
+    %2:_(s32) = COPY $sgpr0
     %3:_(s32) = G_CONSTANT i32 0
     %4:_(s1) = G_TRUNC %0
     %5:_(s1) = G_ICMP intpred(eq), %2, %3

test/CodeGen/AMDGPU/endpgm-dce.mir

@@ -112,6 +112,7 @@ name: call
 tracksRegLiveness: true
 body:             |
   bb.0:
+    liveins: $sgpr2_sgpr3
     $vcc = IMPLICIT_DEF
     $sgpr0_sgpr1 = S_OR_B64 $exec, killed $vcc, implicit-def $scc
     $sgpr4_sgpr5 = S_SWAPPC_B64 $sgpr2_sgpr3

test/CodeGen/AMDGPU/misched-killflags.mir

@@ -3,9 +3,13 @@
 ---
 name: func0
 tracksRegLiveness: true
+machineFunctionInfo:
+  isEntryFunction: true
+  scratchRSrcReg:  '$sgpr0_sgpr1_sgpr2_sgpr3'
+  scratchWaveOffsetReg: '$sgpr7'
+  frameOffsetReg:  '$sgpr7'
 body: |
   bb.0:
-    liveins: $sgpr7, $sgpr0_sgpr1_sgpr2_sgpr3
 
     $sgpr33 = S_MOV_B32 $sgpr7
     $sgpr32 = S_MOV_B32 $sgpr33
@@ -29,7 +33,7 @@ body: |
 # CHECK-DAG: $sgpr10 = S_MOV_B32 5
 # CHECK-DAG: $sgpr9 = S_MOV_B32 4
 # CHECK-DAG: $sgpr8 = S_MOV_B32 3
-# CHECK-DAG: $sgpr33 = S_MOV_B32 killed $sgpr7
+# CHECK-DAG: $sgpr33 = S_MOV_B32 $sgpr7
 # CHECK: $vgpr0 = V_MOV_B32_e32 $sgpr8, implicit $exec, implicit-def $vgpr0_vgpr1_vgpr2_vgpr3, implicit $sgpr8_sgpr9_sgpr10_sgpr11
 # CHECK: $sgpr32 = S_MOV_B32 $sgpr33
 # CHECK: BUNDLE implicit-def $sgpr6_sgpr7, implicit-def $sgpr6, implicit-def $sgpr7, implicit-def $scc {
@@ -41,5 +45,5 @@ body: |
 # CHECK: $vgpr1 = V_MOV_B32_e32 $sgpr9, implicit $exec, implicit $sgpr8_sgpr9_sgpr10_sgpr11
 # CHECK: $vgpr2 = V_MOV_B32_e32 $sgpr10, implicit $exec, implicit $sgpr8_sgpr9_sgpr10_sgpr11
 # CHECK: $vgpr3 = V_MOV_B32_e32 killed $sgpr11, implicit $exec, implicit $sgpr8_sgpr9_sgpr10_sgpr11, implicit $exec
-# CHECK: S_NOP 0, implicit killed $sgpr6_sgpr7, implicit $sgpr0_sgpr1_sgpr2_sgpr3, implicit $sgpr4, implicit killed $vgpr0_vgpr1_vgpr2_vgpr3
+# CHECK: S_NOP 0, implicit $sgpr6_sgpr7, implicit $sgpr0_sgpr1_sgpr2_sgpr3, implicit killed $sgpr4, implicit killed $vgpr0_vgpr1_vgpr2_vgpr3
 # CHECK: S_ENDPGM 0

test/CodeGen/AMDGPU/rename-independent-subregs-mac-operands.mir

@@ -11,6 +11,11 @@ legalized:       false
 regBankSelected: false
 selected:        false
 tracksRegLiveness: true
+machineFunctionInfo:
+  scratchRSrcReg:  '$sgpr0_sgpr1_sgpr2_sgpr3'
+  scratchWaveOffsetReg: '$sgpr4'
+  frameOffsetReg:  '$sgpr4'
+
 registers:
   - { id: 0, class: vreg_128 }
   - { id: 1, class: vreg_128 }
@@ -92,6 +97,10 @@ legalized:       false
 regBankSelected: false
 selected:        false
 tracksRegLiveness: true
+machineFunctionInfo:
+  scratchRSrcReg:  '$sgpr0_sgpr1_sgpr2_sgpr3'
+  scratchWaveOffsetReg: '$sgpr4'
+  frameOffsetReg:  '$sgpr4'
 registers:
   - { id: 0, class: vgpr_32, preferred-register: '' }
   - { id: 1, class: vgpr_32, preferred-register: '' }
@@ -130,8 +139,7 @@ body:             |
     BUFFER_STORE_DWORD_OFFEN %6.sub1, %0, $sgpr0_sgpr1_sgpr2_sgpr3, $sgpr4, 4, 0, 0, 0, implicit $exec
     BUFFER_STORE_DWORD_OFFEN %6.sub0, %0, $sgpr0_sgpr1_sgpr2_sgpr3, $sgpr4, 0, 0, 0, 0, implicit $exec
     $sgpr30_sgpr31 = COPY %5
-    $sgpr5 = COPY $sgpr5
-    S_SETPC_B64_return $sgpr30_sgpr31, implicit $sgpr5
+    S_SETPC_B64_return $sgpr30_sgpr31
 
 ...
 

test/CodeGen/MIR/AMDGPU/parse-order-reserved-regs.mir

@@ -0,0 +1,29 @@
+# RUN: llc -march=amdgcn -run-pass=none -verify-machineinstrs -o - %s | FileCheck %s
+
+# Previously getReservedRegs was called before parsing
+# machineFunctionInfo, but the AMDGPU implementation depends on
+# setting register fields to reserve there. $sgpr50 would then not be
+# reserved, resulting in a verifier error from an undefined register.
+
+---
+# CHECK: machineFunctionInfo:
+# CHECK: isEntryFunction: true
+# CHECK: scratchRSrcReg:  '$sgpr0_sgpr1_sgpr2_sgpr3'
+# CHECK: scratchWaveOffsetReg: '$sgpr50'
+# CHECK: frameOffsetReg:  '$sgpr50'
+# CHECK: renamable $vgpr0 = BUFFER_LOAD_DWORD_OFFEN %stack.0, $sgpr0_sgpr1_sgpr2_sgpr3, $sgpr50, 4, 0, 0, 0, implicit $exec :: (load 4, addrspace 5)
+name: reserve_correct_register
+tracksRegLiveness: true
+machineFunctionInfo:
+  isEntryFunction: true
+  scratchRSrcReg:  '$sgpr0_sgpr1_sgpr2_sgpr3'
+  scratchWaveOffsetReg: '$sgpr50'
+  frameOffsetReg:  '$sgpr50'
+stack:
+  - { id: 0, type: default, offset: 0, size: 4, alignment: 4 }
+
+body:             |
+  bb.0:
+    renamable $vgpr0 = BUFFER_LOAD_DWORD_OFFEN %stack.0, $sgpr0_sgpr1_sgpr2_sgpr3, $sgpr50, 4, 0, 0, 0, implicit $exec :: (load 4, addrspace 5)
+    S_ENDPGM 0
+...