- Objective-C constant strings were being
NULL-terminated erroneously.
- Empty Objective-C constant strings were not
being generated correctly.
Also added the template for a test of these
fixes.
llvm-svn: 125314
AST/PCH files more lazy:
- Don't preload all of the file source-location entries when reading
the AST file. Instead, load them lazily, when needed.
- Only look up header-search information (whether a header was already
#import'd, how many times it's been included, etc.) when it's needed
by the preprocessor, rather than pre-populating it.
Previously, we would pre-load all of the file source-location entries,
which also populated the header-search information structure. This was
a relatively minor performance issue, since we would end up stat()'ing
all of the headers stored within a AST/PCH file when the AST/PCH file
was loaded. In the normal PCH use case, the stat()s were cached, so
the cost--of preloading ~860 source-location entries in the Cocoa.h
case---was relatively low.
However, the recent optimization that replaced stat+open with
open+fstat turned this into a major problem, since the preloading of
source-location entries would now end up opening those files. Worse,
those files wouldn't be closed until the file manager was destroyed,
so just opening a Cocoa.h PCH file would hold on to ~860 file
descriptors, and it was easy to blow through the process's limit on
the number of open file descriptors.
By eliminating the preloading of these files, we neither open nor stat
the headers stored in the PCH/AST file until they're actually needed
for something. Concretely, we went from
*** HeaderSearch Stats:
835 files tracked.
364 #import/#pragma once files.
823 included exactly once.
6 max times a file is included.
3 #include/#include_next/#import.
0 #includes skipped due to the multi-include optimization.
1 framework lookups.
0 subframework lookups.
*** Source Manager Stats:
835 files mapped, 3 mem buffers mapped.
37460 SLocEntry's allocated, 11215575B of Sloc address space used.
62 bytes of files mapped, 0 files with line #'s computed.
with a trivial program that uses a chained PCH including a Cocoa PCH
to
*** HeaderSearch Stats:
4 files tracked.
1 #import/#pragma once files.
3 included exactly once.
2 max times a file is included.
3 #include/#include_next/#import.
0 #includes skipped due to the multi-include optimization.
1 framework lookups.
0 subframework lookups.
*** Source Manager Stats:
3 files mapped, 3 mem buffers mapped.
37460 SLocEntry's allocated, 11215575B of Sloc address space used.
62 bytes of files mapped, 0 files with line #'s computed.
for the same program.
llvm-svn: 125286
gep to explicit addressing, we know that none of the intermediate
computation overflows.
This could use review: it seems that the shifts certainly wouldn't
overflow, but could the intermediate adds overflow if there is a
negative index?
Previously the testcase would instcombine to:
define i1 @test(i64 %i) {
%p1.idx.mask = and i64 %i, 4611686018427387903
%cmp = icmp eq i64 %p1.idx.mask, 1000
ret i1 %cmp
}
now we get:
define i1 @test(i64 %i) {
%cmp = icmp eq i64 %i, 1000
ret i1 %cmp
}
llvm-svn: 125271
linkage into Decl.cpp. Disable this logic for extern "C" functions, because
the operative rule there is weaker. Fixes rdar://problem/8898466
llvm-svn: 125268
exact/nsw/nuw shifts and have instcombine infer them when it can prove
that the relevant properties are true for a given shift without them.
Also, a variety of refactoring to use the new patternmatch logic thrown
in for good luck. I believe that this takes care of a bunch of related
code quality issues attached to PR8862.
llvm-svn: 125267
optimizations to be much more aggressive in the face of
exact/nsw/nuw div and shifts. For example, these (which
are the same except the first is 'exact' sdiv:
define i1 @sdiv_icmp4_exact(i64 %X) nounwind {
%A = sdiv exact i64 %X, -5 ; X/-5 == 0 --> x == 0
%B = icmp eq i64 %A, 0
ret i1 %B
}
define i1 @sdiv_icmp4(i64 %X) nounwind {
%A = sdiv i64 %X, -5 ; X/-5 == 0 --> x == 0
%B = icmp eq i64 %A, 0
ret i1 %B
}
compile down to:
define i1 @sdiv_icmp4_exact(i64 %X) nounwind {
%1 = icmp eq i64 %X, 0
ret i1 %1
}
define i1 @sdiv_icmp4(i64 %X) nounwind {
%X.off = add i64 %X, 4
%1 = icmp ult i64 %X.off, 9
ret i1 %1
}
This happens when you do something like:
(ptr1-ptr2) == 42
where the pointers are pointers to non-unit types.
llvm-svn: 125266
and generally tidying things up. Only very trivial functionality changes
like now doing (-1 - A) -> (~A) for vectors too.
InstCombineAddSub.cpp | 296 +++++++++++++++++++++-----------------------------
1 file changed, 126 insertions(+), 170 deletions(-)
llvm-svn: 125264
Bruno Cardoso Lopes