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| author | Xi Wang <xi.wang@gmail.com> | 2013-05-16 02:33:46 -0400 |
|---|---|---|
| committer | Pekka Enberg <penberg@kernel.org> | 2013-05-18 10:33:55 +0300 |
| commit | 0448f78f5fae84b8a9c1358129a03ea24e593b34 (patch) | |
| tree | 68ff78614b2a9bc516edd388574f0f3a3954a6f1 /validation/backend/loop2.c | |
| parent | 5449cfbfe55eea2a602a40122c122b5040d67243 (diff) | |
| download | sparse-dev-0448f78f5fae84b8a9c1358129a03ea24e593b34.tar.gz | |
sparse, llvm: fix phi generation
PHI in LLVM is different from that in sparse. LLVM requires PHI "for
each predecessor basic block of the current block" even if the current
block doesn't use it. It's tricky to correctly place PHI.
This patch implements a simpler and safer strategy:
1) allocate an alloca for each phi, and
2) translate phi/phisrc to load/store alloca.
LLVM optimizations will promote load/store to registers.
Cc: Christopher Li <sparse@chrisli.org>
Cc: Jeff Garzik <jgarzik@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Diffstat (limited to 'validation/backend/loop2.c')
| -rw-r--r-- | validation/backend/loop2.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/validation/backend/loop2.c b/validation/backend/loop2.c new file mode 100644 index 00000000..279af214 --- /dev/null +++ b/validation/backend/loop2.c @@ -0,0 +1,14 @@ +extern int op(void); + +static void test(void) +{ + int i; + for (i = 0; ; i++) { + op(); + } +} + +/* + * check-name: Loops with unused counter + * check-command: ./sparsec -c $file -o tmp.o + */ |