[llvm] r355426 - AMDGPU: Preserve undef flag when expanding SI_IF

[Matt Arsenault via llvm-commits]

Author: arsenm
Date: Tue Mar  5 10:38:00 2019
New Revision: 355426

URL: http://llvm.org/viewvc/llvm-project?rev=355426&view=rev
Log:
AMDGPU: Preserve undef flag when expanding SI_IF

Fixes undefined value verifier error.

Modified:
    llvm/trunk/lib/Target/AMDGPU/SILowerControlFlow.cpp
    llvm/trunk/test/CodeGen/AMDGPU/si-lower-control-flow.mir

Modified: llvm/trunk/lib/Target/AMDGPU/SILowerControlFlow.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AMDGPU/SILowerControlFlow.cpp?rev=355426&r1=355425&r2=355426&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AMDGPU/SILowerControlFlow.cpp (original)
+++ llvm/trunk/lib/Target/AMDGPU/SILowerControlFlow.cpp Tue Mar  5 10:38:00 2019
@@ -199,8 +199,8 @@ void SILowerControlFlow::emitIf(MachineI
   MachineInstr *And =
     BuildMI(MBB, I, DL, TII->get(AMDGPU::S_AND_B64), Tmp)
     .addReg(CopyReg)
-    //.addReg(AMDGPU::EXEC)
-    .addReg(Cond.getReg());
+    .add(Cond);
+
   setImpSCCDefDead(*And, true);
 
   MachineInstr *Xor = nullptr;

Modified: llvm/trunk/test/CodeGen/AMDGPU/si-lower-control-flow.mir
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AMDGPU/si-lower-control-flow.mir?rev=355426&r1=355425&r2=355426&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AMDGPU/si-lower-control-flow.mir (original)
+++ llvm/trunk/test/CodeGen/AMDGPU/si-lower-control-flow.mir Tue Mar  5 10:38:00 2019
@@ -1,23 +1,53 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
 # RUN: llc -mtriple=amdgcn-amd-amdhsa -run-pass=si-lower-control-flow -verify-machineinstrs %s -o - | FileCheck -check-prefixes=GCN %s
 
 # Check that assert is not triggered
-# GCN-LABEL: name: si-lower-control-flow{{$}}
-# GCN-CHECK: S_LOAD_DWORD_IMM
-
---- |
-
-  define amdgpu_kernel void @si-lower-control-flow() {
-    ret void
-  }
 
 ...
 ---
 name: si-lower-control-flow
 body: |
   bb.0:
+    ; GCN-LABEL: name: si-lower-control-flow
+    ; GCN: [[COPY:%[0-9]+]]:sgpr_64 = COPY $sgpr4_sgpr5
+    ; GCN: [[S_LOAD_DWORD_IMM:%[0-9]+]]:sreg_32_xm0_xexec = S_LOAD_DWORD_IMM [[COPY]], 16, 0
+    ; GCN: [[S_AND_B32_:%[0-9]+]]:sreg_32_xm0 = S_AND_B32 [[S_LOAD_DWORD_IMM]], 255, implicit-def $scc
+    ; GCN: [[S_AND_B32_1:%[0-9]+]]:sreg_32_xm0 = S_AND_B32 65535, [[S_AND_B32_]], implicit-def $scc
+    ; GCN: S_ENDPGM
     %0:sgpr_64 = COPY $sgpr4_sgpr5
     %1:sreg_32_xm0_xexec = S_LOAD_DWORD_IMM %0, 16, 0
     %2:sreg_32_xm0 = S_AND_B32 %1, 255, implicit-def $scc
     %3:sreg_32_xm0 = S_AND_B32 65535, %2, implicit-def $scc
     S_ENDPGM
 ...
+
+---
+name: preserve_undef_flag_si_if_src
+tracksRegLiveness: true
+body:             |
+  ; GCN-LABEL: name: preserve_undef_flag_si_if_src
+  ; GCN: bb.0:
+  ; GCN:   successors: %bb.1(0x40000000), %bb.2(0x40000000)
+  ; GCN:   [[COPY:%[0-9]+]]:sreg_64 = COPY $exec, implicit-def $exec
+  ; GCN:   [[S_AND_B64_:%[0-9]+]]:sreg_64 = S_AND_B64 [[COPY]], undef %1:sreg_64, implicit-def dead $scc
+  ; GCN:   [[S_XOR_B64_:%[0-9]+]]:sreg_64 = S_XOR_B64 [[S_AND_B64_]], [[COPY]], implicit-def dead $scc
+  ; GCN:   $exec = S_MOV_B64_term killed [[S_AND_B64_]]
+  ; GCN:   SI_MASK_BRANCH %bb.2, implicit $exec
+  ; GCN:   S_BRANCH %bb.1
+  ; GCN: bb.1:
+  ; GCN:   successors: %bb.2(0x80000000)
+  ; GCN: bb.2:
+  ; GCN:   S_ENDPGM
+  bb.0:
+    successors: %bb.1, %bb.2
+
+    %1:sreg_64 = SI_IF undef %0:sreg_64, %bb.2, implicit-def dead $exec, implicit-def dead $scc, implicit $exec
+    S_BRANCH %bb.1
+
+  bb.1:
+    successors: %bb.2
+
+  bb.2:
+    S_ENDPGM
+
+...