This tends to happen a lot with bitfield code generated by clang. A simple example for x86_64 is
uint64_t foo(uint64_t x) { return (x&1) << 42; }
which used to compile into bloated code:
shlq $42, %rdi ## encoding: [0x48,0xc1,0xe7,0x2a]
movabsq $4398046511104, %rax ## encoding: [0x48,0xb8,0x00,0x00,0x00,0x00,0x00,0x04,0x00,0x00]
andq %rdi, %rax ## encoding: [0x48,0x21,0xf8]
ret ## encoding: [0xc3]
with this patch we can fold the immediate into the and:
andq $1, %rdi ## encoding: [0x48,0x83,0xe7,0x01]
movq %rdi, %rax ## encoding: [0x48,0x89,0xf8]
shlq $42, %rax ## encoding: [0x48,0xc1,0xe0,0x2a]
ret ## encoding: [0xc3]
It's possible to save another byte by using 'andl' instead of 'andq' but I currently see no way of doing
that without making this code even more complicated. See the TODOs in the code.
llvm-svn: 129990
set by default when dumping registers. If you want to see all of the register
sets you can use the "--all" option:
(lldb) register read --all
If you want to just see some register sets, you can currently specify them
by index:
(lldb) register read --set 0 --set 2
We need to get shorter register set names soon so we can specify the register
sets by name without having to type too much. I will make this change soon.
You can also have any integer encoded registers resolve the address values
back to any code or data from the object files using the "--lookup" option.
Below is sample output when stopped in the libc function "puts" with some
const strings in registers:
Process 8973 stopped
* thread #1: tid = 0x2c03, 0x00007fff828fa30f libSystem.B.dylib`puts + 1, stop reason = instruction step into
frame #0: 0x00007fff828fa30f libSystem.B.dylib`puts + 1
(lldb) register read --lookup
General Purpose Registers:
rax = 0x0000000100000e98 "----------------------------------------------------------------------"
rbx = 0x0000000000000000
rcx = 0x0000000000000001
rdx = 0x0000000000000000
rdi = 0x0000000100000e98 "----------------------------------------------------------------------"
rsi = 0x0000000100800000
rbp = 0x00007fff5fbff710
rsp = 0x00007fff5fbff280
r8 = 0x0000000000000040
r9 = 0x0000000000000000
r10 = 0x0000000000000000
r11 = 0x0000000000000246
r12 = 0x0000000000000000
r13 = 0x0000000000000000
r14 = 0x0000000000000000
r15 = 0x0000000000000000
rip = 0x00007fff828fa30f libSystem.B.dylib`puts + 1
rflags = 0x0000000000000246
cs = 0x0000000000000027
fs = 0x0000000000000000
gs = 0x0000000000000000
As we can see, we see two constant strings and the PC (register "rip") is
showing the code it resolves to.
I fixed the register "--format" option to work as expected.
Added a setting to disable skipping the function prologue when setting
breakpoints as a target settings variable:
(lldb) settings set target.skip-prologue false
Updated the user settings controller boolean value handler funciton to be able
to take the default value so it can correctly respond to the eVarSetOperationClear
operation.
Did some usability work on the OptionValue classes.
Fixed the "image lookup" command to correctly respond to the "--verbose"
option and display the detailed symbol context information when looking up
line table entries and functions by name. This previously was only working
for address lookups.
llvm-svn: 129977
add <rd>, sp, #<imm8>
ldr <rd>, [sp, #<imm8>]
When the offset from sp is multiple of 4 and in range of 0-1020.
This saves code size by utilizing 16-bit instructions.
rdar://9321541
llvm-svn: 129971
An exception is thrown via a call to _cxa_throw, which we don't expect to
return. Therefore, the "true" part of the invoke goes to a BB that has
'unreachable' as its only instruction. This is lowered into an empty MachineBB.
The landing pad for this invoke, however, is directly after the "true" MBB.
When the empty MBB is removed, the landing pad is directly below the BB with the
invoke call. The unconditional branch is removed and then the two blocks are
merged together.
The testcase is too big for a regression test.
<rdar://problem/9305728>
llvm-svn: 129965
rather than calling "process kill" explicitly at the end of the test.
The test might not even reach the end because it could have failed prematurely.
llvm-svn: 129963
compile time) and .gcda emission (at runtime). --coverage enables both.
This does not yet add the profile_rt library to the link step if -fprofile-arcs
is enabled when linking.
llvm-svn: 129956
and TestAliases.py. Pass the keyword argument 'check=False' to:
self.runCmd("script my.date()", check=False)
since we want to restore sys.stdout no matter what the outcome of the runCmd is.
llvm-svn: 129949
Ted Kremenek