gcc's unused warnings which don't get emitted if the function is referenced even in an unevaluated context
(e.g. in templates, sizeof, etc.). Also, saying that a function is 'unused' because it won't get codegen'ed
is somewhat misleading.
- Don't emit 'unused' warnings for functions that are referenced in any part of the user's code.
- A warning that an internal function/variable won't get emitted is useful though, so introduce
-Wunneeded-internal-declaration which will warn if a function/variable with internal linkage is not
"needed" ('used' from the codegen perspective), e.g:
static void foo() { }
template <int>
void bar() {
foo();
}
test.cpp:1:13: warning: function 'foo' is not needed and will not be emitted
static void foo() { }
^
Addresses rdar://8733476.
llvm-svn: 129794
currently in trace mode (-t to dotest.py), i.e., tracing the lldb command execution.
Change TestInferiorCrashing.inferior_crashing_python(self) to check this flag in
order to print the stack trace of the inferior thread.
llvm-svn: 129785
CL_AddressableVoid is the expression classification used for void
expressions whose address can be taken, i.e. the result of [], *
or void variable references in C, as opposed to things like the
result of a void function call.
llvm-svn: 129783
Making use of VFP / NEON floating point multiply-accumulate / subtraction is
difficult on current ARM implementations for a few reasons.
1. Even though a single vmla has latency that is one cycle shorter than a pair
of vmul + vadd, a RAW hazard during the first (4? on Cortex-a8) can cause
additional pipeline stall. So it's frequently better to single codegen
vmul + vadd.
2. A vmla folowed by a vmul, vmadd, or vsub causes the second fp instruction to
stall for 4 cycles. We need to schedule them apart.
3. A vmla followed vmla is a special case. Obvious issuing back to back RAW
vmla + vmla is very bad. But this isn't ideal either:
vmul
vadd
vmla
Instead, we want to expand the second vmla:
vmla
vmul
vadd
Even with the 4 cycle vmul stall, the second sequence is still 2 cycles
faster.
Up to now, isel simply avoid codegen'ing fp vmla / vmls. This works well enough
but it isn't the optimial solution. This patch attempts to make it possible to
use vmla / vmls in cases where it is profitable.
A. Add missing isel predicates which cause vmla to be codegen'ed.
B. Make sure the fmul in (fadd (fmul)) has a single use. We don't want to
compute a fmul and a fmla.
C. Add additional isel checks for vmla, avoid cases where vmla is feeding into
fp instructions (except for the #3 exceptional case).
D. Add ARM hazard recognizer to model the vmla / vmls hazards.
E. Add a special pre-regalloc case to expand vmla / vmls when it's likely the
vmla / vmls will trigger one of the special hazards.
Enable these fp vmlx codegen changes for Cortex-A9.
llvm-svn: 129775
Add a avoidWriteAfterWrite() target hook to identify register classes that
suffer from write-after-write hazards. For those register classes, try to avoid
writing the same register in two consecutive instructions.
This is currently disabled by default. We should not spill to avoid hazards!
The command line flag -avoid-waw-hazard can be used to enable waw avoidance.
llvm-svn: 129772
when they are a truncate from something else. This eliminates fully half of all the
fastisel rejections on a test c++ file I'm working with, which should make a substantial
improvement for -O0 compile of c++ code.
This fixed rdar://9297003 - fast isel bails out on all functions taking bools
llvm-svn: 129752
Before we would bail out on i1 arguments all together, now we just bail on
non-constant ones. Also, we used to emit extraneous code. e.g. test12 was:
movb $0, %al
movzbl %al, %edi
callq _test12
and test13 was:
movb $0, %al
xorl %edi, %edi
movb %al, 7(%rsp)
callq _test13f
Now we get:
movl $0, %edi
callq _test12
and:
movl $0, %edi
callq _test13f
llvm-svn: 129751
line tables specify breakpoints can be set in the source. When dumping the
source, the number of breakpoints that can be set on a source line are shown
as a prefix:
(lldb) source list -f test.c -l1 -c222 -b
1 #include <stdio.h>
2 #include <sys/fcntl.h>
3 #include <unistd.h>
4 int
5 sleep_loop (const int num_secs)
[2] 6 {
7 int i;
[1] 8 for (i=0; i<num_secs; ++i)
9 {
[1] 10 printf("%d of %i - sleep(1);\n", i, num_secs);
[1] 11 sleep(1);
12 }
13 return 0;
[1] 14 }
15
16 int
17 main (int argc, char const* argv[])
[1] 18 {
[1] 19 printf("Process: %i\n\n", getpid());
[1] 20 puts("Press any key to continue..."); getchar();
[1] 21 sleep_loop (20);
22 return 12;
[1] 23 }
Above we can see there are two breakpoints for line 6 and one breakpoint for
lines 8, 10, 11, 14, 18, 19, 20, 21 and 23. All other lines have no line table
entries for them. This helps visualize the data provided in the debug
information without having to manually dump all line tables. It also includes
all inline breakpoint that may result for a given file which can also be very
handy to see.
llvm-svn: 129747
is, it assumes addresses are 64-bit aligned (which should be the more common
case). If the alignment is found not to be aligned, then getOperandLatency()
would adjust the operand latency computation by one to compensate for it.
rdar://9294833
llvm-svn: 129742
Daniel Dunbar