// Look for values being erased.
bool DidPrune = false;
for (unsigned i = 0, e = LR.getNumValNums(); i != e; ++i) {
- if (Vals[i].Resolution != CR_Erase)
+ // We should trigger in all cases in which eraseInstrs() does something.
+ // match what eraseInstrs() is doing, print a message so
+ if (Vals[i].Resolution != CR_Erase &&
+ (Vals[i].Resolution != CR_Keep || !Vals[i].ErasableImplicitDef ||
+ !Vals[i].Pruned))
continue;
// Check subranges at the point where the copy will be removed.
SlotIndex Def = LR.getValNumInfo(i)->def;
+ // Print message so mismatches with eraseInstrs() can be diagnosed.
+ DEBUG(dbgs() << "\t\tExpecting instruction removal at " << Def << '\n');
for (LiveInterval::SubRange &S : LI.subranges()) {
LiveQueryResult Q = S.Query(Def);
--- /dev/null
+# RUN: llc -o - %s -mtriple=amdgcn-amd-amdhsa-opencl -run-pass=simple-register-coalescing | FileCheck %s
+---
+# Checks for a bug where subregister liveranges were not properly pruned for
+# an IMPLCITI_DEF that gets removed completely.
+#
+# CHECK-LABEL: name: func
+# IMPLICIT_DEF should be gone without llc hitting assertion failures.
+# CHECK-NOT: IMPLCITI_DEF
+name: func
+tracksRegLiveness: true
+body: |
+ bb.0:
+ undef %5.sub1 = V_MOV_B32_e32 0, implicit %exec
+ %6 = COPY %5
+ S_CBRANCH_VCCZ %bb.2, implicit undef %vcc
+
+ bb.1:
+ %1 : sreg_32_xm0 = S_MOV_B32 0
+ undef %0.sub0 : sreg_64 = COPY %1
+ %0.sub1 = COPY %1
+ %4 : vreg_64 = COPY killed %0
+ %5 : vreg_64 = IMPLICIT_DEF
+ %6 : vreg_64 = COPY killed %4
+
+ bb.2:
+ %2 : vgpr_32 = V_CVT_F32_I32_e32 killed %5.sub1, implicit %exec
+
+ bb.3:
+ %3 : vgpr_32 = V_CVT_F32_I32_e32 killed %6.sub1, implicit %exec
+ S_ENDPGM
+...