[PPC64] Bug fix: when enabling sibling-call-opt and shrink-wrapping, the tail call branch instruction might disappear
Bug Pattern:
# BB#0: # %entry
cmpldi 3, 0
beq- 0, .LBB0_2
# BB#1: # %exit
lwz 4, 0(3)
#TC_RETURNd8 LVComputationKind 0
.LBB0_2: # %cond.false
mflr 0
std 0, 16(1)
stdu 1, -96(1)
.Ltmp0:
.cfi_def_cfa_offset 96
.Ltmp1:
.cfi_offset lr, 16
bl __assert_fail
nop
The branch instruction for tail call return is not generated, because the
shrink-wrapping pass choosing a new Restore Point: %cond.false, so %exit
block is not sent to emitEpilogue, that's why the branch is not generated.
Thanks Kit's opinions!
Reviewers: nemanjai hfinkel tjablin kbarton
http://reviews.llvm.org/D17606
llvm-svn: 265112