https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97682
Bug ID: 97682
Summary: Miscompiled tail call with -fPIC
Product: gcc
Version: 10.2.1
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: sch...@linux-m68k.org
Target Milestone: ---
Target: riscv64-*-*
Created attachment 49488
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=49488&action=edit
BlockFrequencyInfo.ii
When the attached file is compiled with -fPIC -O3, the tail call to
std::vector<llvm::BlockFrequencyInfoImplBase::FrequencyData,
std::allocator<llvm::BlockFrequencyInfoImplBase::FrequencyData>
>::_M_default_append(unsigned long) is missing in
llvm::BlockFrequencyInfoImpl<llvm::BasicBlock>::initializeRPOT():
.L2924:
li t1,4096 #,
add sp,sp,t1 #,,
ld ra,376(sp) #,
ld s0,368(sp) #,
ld s1,360(sp) #,
ld s3,344(sp) #,
ld s4,336(sp) #,
ld s5,328(sp) #,
ld s6,320(sp) #,
ld s7,312(sp) #,
ld s8,304(sp) #,
ld s9,296(sp) #,
ld s10,288(sp) #,
ld s11,280(sp) #,
# /usr/include/c++/10/bits/stl_vector.h:940: _M_default_append(__new_size
- size());
addi a0,s2,8 #,, this
ld s2,352(sp) #,
# /usr/include/c++/10/bits/stl_vector.h:940: _M_default_append(__new_size
- size());
sub a1,a5,a1 #, _680, tmp1548
addi sp,sp,384 #,,
# /usr/include/c++/10/bits/stl_vector.h:940: _M_default_append(__new_size
- size());
jr t1 #
Without -fPIC, the last line has the correct tail call:
tail
_ZNSt6vectorIN4llvm26BlockFrequencyInfoImplBase13FrequencyDataESaIS2_EE17_M_default_appendEm
#
