[llvm] 5316256 - AMDGPU/GlobalISel: Fix assert on copy to vcc

[Matt Arsenault via llvm-commits]

Author: Matt Arsenault
Date: 2020-08-06T09:41:14-04:00
New Revision: 53162567090251e98b14f979ee2f69669cec3ddd

URL: https://github.com/llvm/llvm-project/commit/53162567090251e98b14f979ee2f69669cec3ddd
DIFF: https://github.com/llvm/llvm-project/commit/53162567090251e98b14f979ee2f69669cec3ddd.diff

LOG: AMDGPU/GlobalISel: Fix assert on copy to vcc

This was trying to constrain a physical register. By the verifier's
understanding, it's impossible to have a 1-bit copy to vcc/vcc_lo so
don't try to handle physregs.

Added: 
    

Modified: 
    llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp
    llvm/test/CodeGen/AMDGPU/GlobalISel/inst-select-copy.mir

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp b/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp
index d3e792b5832b..89bcd39cc60c 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp
@@ -77,8 +77,9 @@ void AMDGPUInstructionSelector::setupMF(MachineFunction &MF, GISelKnownBits &KB,
 
 bool AMDGPUInstructionSelector::isVCC(Register Reg,
                                       const MachineRegisterInfo &MRI) const {
-  if (Register::isPhysicalRegister(Reg))
-    return Reg == TRI.getVCC();
+  // The verifier is oblivious to s1 being a valid value for wavesize registers.
+  if (Reg.isPhysical())
+    return false;
 
   auto &RegClassOrBank = MRI.getRegClassOrRegBank(Reg);
   const TargetRegisterClass *RC =

diff  --git a/llvm/test/CodeGen/AMDGPU/GlobalISel/inst-select-copy.mir b/llvm/test/CodeGen/AMDGPU/GlobalISel/inst-select-copy.mir
index f8a7fc8bd6f8..f8eb541beff1 100644
--- a/llvm/test/CodeGen/AMDGPU/GlobalISel/inst-select-copy.mir
+++ b/llvm/test/CodeGen/AMDGPU/GlobalISel/inst-select-copy.mir
@@ -239,3 +239,97 @@ body: |
     S_ENDPGM 0, implicit %2
 
 ...
+
+---
+
+name:            copy_s64_to_vcc
+legalized:       true
+regBankSelected: true
+
+
+body: |
+  bb.0:
+    liveins: $sgpr0_sgpr1
+    ; WAVE64-LABEL: name: copy_s64_to_vcc
+    ; WAVE64: [[COPY:%[0-9]+]]:sreg_64 = COPY $sgpr0_sgpr1
+    ; WAVE64: $vcc = COPY [[COPY]]
+    ; WAVE64: S_ENDPGM 0, implicit $vcc
+    ; WAVE32-LABEL: name: copy_s64_to_vcc
+    ; WAVE32: $vcc_hi = IMPLICIT_DEF
+    ; WAVE32: [[COPY:%[0-9]+]]:sreg_64 = COPY $sgpr0_sgpr1
+    ; WAVE32: $vcc = COPY [[COPY]]
+    ; WAVE32: S_ENDPGM 0, implicit $vcc_lo
+    %0:sgpr(s64) = COPY $sgpr0_sgpr1
+    $vcc = COPY %0
+    S_ENDPGM 0, implicit $vcc
+
+...
+
+---
+
+name:            copy_s32_to_vcc_lo
+legalized:       true
+regBankSelected: true
+
+
+body: |
+  bb.0:
+    liveins: $sgpr0
+    ; WAVE64-LABEL: name: copy_s32_to_vcc_lo
+    ; WAVE64: [[COPY:%[0-9]+]]:sreg_32 = COPY $sgpr0
+    ; WAVE64: $vcc_lo = COPY [[COPY]]
+    ; WAVE64: S_ENDPGM 0, implicit $vcc
+    ; WAVE32-LABEL: name: copy_s32_to_vcc_lo
+    ; WAVE32: $vcc_hi = IMPLICIT_DEF
+    ; WAVE32: [[COPY:%[0-9]+]]:sreg_32 = COPY $sgpr0
+    ; WAVE32: $vcc_lo = COPY [[COPY]]
+    ; WAVE32: S_ENDPGM 0, implicit $vcc_lo
+    %0:sgpr(s32) = COPY $sgpr0
+    $vcc_lo = COPY %0
+    S_ENDPGM 0, implicit $vcc
+
+...
+
+---
+
+name:            copy_vcc_to_s64
+legalized:       true
+regBankSelected: true
+
+
+body: |
+  bb.0:
+    liveins: $vcc
+    ; WAVE64-LABEL: name: copy_vcc_to_s64
+    ; WAVE64: [[COPY:%[0-9]+]]:sreg_64 = COPY $vcc
+    ; WAVE64: S_ENDPGM 0, implicit [[COPY]]
+    ; WAVE32-LABEL: name: copy_vcc_to_s64
+    ; WAVE32: $vcc_hi = IMPLICIT_DEF
+    ; WAVE32: [[COPY:%[0-9]+]]:sreg_64 = COPY $vcc
+    ; WAVE32: S_ENDPGM 0, implicit [[COPY]]
+    %0:sgpr(s64) = COPY $vcc
+    S_ENDPGM 0, implicit %0
+
+...
+
+---
+
+name:            copy_vcc_lo_to_s32
+legalized:       true
+regBankSelected: true
+
+
+body: |
+  bb.0:
+    liveins: $vcc
+    ; WAVE64-LABEL: name: copy_vcc_lo_to_s32
+    ; WAVE64: [[COPY:%[0-9]+]]:sreg_32 = COPY $vcc_lo
+    ; WAVE64: S_ENDPGM 0, implicit [[COPY]]
+    ; WAVE32-LABEL: name: copy_vcc_lo_to_s32
+    ; WAVE32: $vcc_hi = IMPLICIT_DEF
+    ; WAVE32: [[COPY:%[0-9]+]]:sreg_32 = COPY $vcc_lo
+    ; WAVE32: S_ENDPGM 0, implicit [[COPY]]
+    %0:sgpr(s32) = COPY $vcc_lo
+    S_ENDPGM 0, implicit %0
+
+...