[llvm] af162ac - AMDGPU/GlobalISel: Fix using readfirstlane with ballot intrinsics

[Matt Arsenault via llvm-commits]

Author: Matt Arsenault
Date: 2020-08-17T09:53:25-04:00
New Revision: af162ac785dd6aa371afc0f111544c82d72c5242

URL: https://github.com/llvm/llvm-project/commit/af162ac785dd6aa371afc0f111544c82d72c5242
DIFF: https://github.com/llvm/llvm-project/commit/af162ac785dd6aa371afc0f111544c82d72c5242.diff

LOG: AMDGPU/GlobalISel: Fix using readfirstlane with ballot intrinsics

This should use the default mapping and insert a copy to the vcc bank,
and not try to insert a readfirstlane.

Added: 
    llvm/test/CodeGen/AMDGPU/GlobalISel/regbankselect-amdgcn.ballot.i64.mir

Modified: 
    llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp b/llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp
index eb41e56ff519..8f0f53df7a54 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp
@@ -2987,7 +2987,6 @@ void AMDGPURegisterBankInfo::applyMappingImpl(
       constrainOpWithReadfirstlane(MI, MRI, 3); // Index
       return;
     }
-    case Intrinsic::amdgcn_ballot:
     case Intrinsic::amdgcn_interp_p1:
     case Intrinsic::amdgcn_interp_p2:
     case Intrinsic::amdgcn_interp_mov:
@@ -3015,6 +3014,9 @@ void AMDGPURegisterBankInfo::applyMappingImpl(
     case Intrinsic::amdgcn_ubfe:
       applyMappingBFEIntrinsic(OpdMapper, false);
       return;
+    case Intrinsic::amdgcn_ballot:
+      // Use default handling and insert copy to vcc source.
+      break;
     }
     break;
   }

diff  --git a/llvm/test/CodeGen/AMDGPU/GlobalISel/regbankselect-amdgcn.ballot.i64.mir b/llvm/test/CodeGen/AMDGPU/GlobalISel/regbankselect-amdgcn.ballot.i64.mir
new file mode 100644
index 000000000000..15e422cf890c
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/GlobalISel/regbankselect-amdgcn.ballot.i64.mir
@@ -0,0 +1,64 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -march=amdgcn -mcpu=fiji -run-pass=regbankselect -regbankselect-fast -verify-machineinstrs -o -  %s | FileCheck %s
+# RUN: llc -march=amdgcn -mcpu=fiji -run-pass=regbankselect -regbankselect-greedy -verify-machineinstrs -o -  %s | FileCheck %s
+
+---
+name:            ballot_sgpr_src
+legalized:       true
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $sgpr0
+    ; CHECK-LABEL: name: ballot_sgpr_src
+    ; CHECK: liveins: $sgpr0
+    ; CHECK: [[COPY:%[0-9]+]]:sgpr(s32) = COPY $sgpr0
+    ; CHECK: [[TRUNC:%[0-9]+]]:sgpr(s1) = G_TRUNC [[COPY]](s32)
+    ; CHECK: [[COPY1:%[0-9]+]]:vcc(s1) = COPY [[TRUNC]](s1)
+    ; CHECK: [[INT:%[0-9]+]]:sgpr(s64) = G_INTRINSIC intrinsic(@llvm.amdgcn.ballot), [[COPY1]](s1)
+    ; CHECK: S_ENDPGM 0, implicit [[INT]](s64)
+    %0:_(s32) = COPY $sgpr0
+    %1:_(s1) = G_TRUNC %0
+    %2:_(s64) = G_INTRINSIC intrinsic(@llvm.amdgcn.ballot), %1
+    S_ENDPGM 0, implicit %2
+...
+
+---
+name:            ballot_vgpr_src
+legalized:       true
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $vgpr0
+    ; CHECK-LABEL: name: ballot_vgpr_src
+    ; CHECK: liveins: $vgpr0
+    ; CHECK: [[COPY:%[0-9]+]]:vgpr(s32) = COPY $vgpr0
+    ; CHECK: [[TRUNC:%[0-9]+]]:vgpr(s1) = G_TRUNC [[COPY]](s32)
+    ; CHECK: [[COPY1:%[0-9]+]]:vcc(s1) = COPY [[TRUNC]](s1)
+    ; CHECK: [[INT:%[0-9]+]]:sgpr(s64) = G_INTRINSIC intrinsic(@llvm.amdgcn.ballot), [[COPY1]](s1)
+    ; CHECK: S_ENDPGM 0, implicit [[INT]](s64)
+    %0:_(s32) = COPY $vgpr0
+    %1:_(s1) = G_TRUNC %0
+    %2:_(s64) = G_INTRINSIC intrinsic(@llvm.amdgcn.ballot), %1
+    S_ENDPGM 0, implicit %2
+...
+
+---
+name:            ballot_vcc_src
+legalized:       true
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $vgpr0, $vgpr1
+    ; CHECK-LABEL: name: ballot_vcc_src
+    ; CHECK: liveins: $vgpr0, $vgpr1
+    ; CHECK: [[COPY:%[0-9]+]]:vgpr(s32) = COPY $vgpr0
+    ; CHECK: [[COPY1:%[0-9]+]]:vgpr(s32) = COPY $vgpr1
+    ; CHECK: [[ICMP:%[0-9]+]]:vcc(s1) = G_ICMP intpred(eq), [[COPY]](s32), [[COPY1]]
+    ; CHECK: [[INT:%[0-9]+]]:sgpr(s64) = G_INTRINSIC intrinsic(@llvm.amdgcn.ballot), [[ICMP]](s1)
+    ; CHECK: S_ENDPGM 0, implicit [[INT]](s64)
+    %0:_(s32) = COPY $vgpr0
+    %1:_(s32) = COPY $vgpr1
+    %2:_(s1) = G_ICMP intpred(eq), %0, %1
+    %3:_(s64) = G_INTRINSIC intrinsic(@llvm.amdgcn.ballot), %2
+    S_ENDPGM 0, implicit %3
+...