[llvm] r308813 - RA: Remove another assert on empty intervals

[Matt Arsenault via llvm-commits]

Author: arsenm
Date: Fri Jul 21 17:24:01 2017
New Revision: 308813

URL: http://llvm.org/viewvc/llvm-project?rev=308813&view=rev
Log:
RA: Remove another assert on empty intervals

This case is similar to the one fixed in r308808,
except when rematerializing.

Fixes bug 33884.

Modified:
    llvm/trunk/lib/CodeGen/InlineSpiller.cpp
    llvm/trunk/test/CodeGen/AMDGPU/spill-empty-live-interval.mir

Modified: llvm/trunk/lib/CodeGen/InlineSpiller.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/InlineSpiller.cpp?rev=308813&r1=308812&r2=308813&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/InlineSpiller.cpp (original)
+++ llvm/trunk/lib/CodeGen/InlineSpiller.cpp Fri Jul 21 17:24:01 2017
@@ -643,8 +643,8 @@ void InlineSpiller::reMaterializeAll() {
       Edit->eraseVirtReg(Reg);
       continue;
     }
-    assert((LIS.hasInterval(Reg) && !LIS.getInterval(Reg).empty()) &&
-           "Reg with empty interval has reference");
+
+    assert(LIS.hasInterval(Reg) && "Reg with no interval");
     RegsToSpill[ResultPos++] = Reg;
   }
   RegsToSpill.erase(RegsToSpill.begin() + ResultPos, RegsToSpill.end());

Modified: llvm/trunk/test/CodeGen/AMDGPU/spill-empty-live-interval.mir
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AMDGPU/spill-empty-live-interval.mir?rev=308813&r1=308812&r2=308813&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AMDGPU/spill-empty-live-interval.mir (original)
+++ llvm/trunk/test/CodeGen/AMDGPU/spill-empty-live-interval.mir Fri Jul 21 17:24:01 2017
@@ -38,3 +38,37 @@ body:             |
     S_ENDPGM
 
 ...
+
+# Similar assert which happens when trying to rematerialize.
+# https://bugs.llvm.org/show_bug.cgi?id=33884
+---
+# CHECK-LABEL: name: rematerialize_empty_interval_has_reference
+
+# CHECK-NOT: MOV
+# CHECK: undef %3.sub2 = V_MOV_B32_e32 1786773504, implicit %exec
+
+# CHECK: bb.1:
+# CHECK-NEXT: S_NOP 0, implicit %3.sub2
+# CHECK-NEXT: S_NOP 0, implicit undef %6.sub0
+# CHECK-NEXT: undef %4.sub2 = V_MOV_B32_e32 0, implicit %exec
+# CHECK-NEXT: S_NOP 0, implicit %4.sub2
+name: rematerialize_empty_interval_has_reference
+tracksRegLiveness: true
+registers:
+  - { id: 0, class: vreg_128, preferred-register: '' }
+  - { id: 1, class: vgpr_32, preferred-register: '' }
+  - { id: 2, class: vgpr_32, preferred-register: '' }
+  - { id: 3, class: vreg_128, preferred-register: '' }
+body:             |
+  bb.0:
+    successors: %bb.1
+
+    undef %0.sub2 = V_MOV_B32_e32 0, implicit %exec
+    undef %3.sub2 = V_MOV_B32_e32 1786773504, implicit %exec
+
+  bb.1:
+    S_NOP 0, implicit %3.sub2
+    S_NOP 0, implicit undef %0.sub0
+    S_NOP 0, implicit %0.sub2
+
+...