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author | Ben Cheng <bccheng@google.com> | 2014-03-25 22:37:19 -0700 |
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committer | Ben Cheng <bccheng@google.com> | 2014-03-25 22:37:19 -0700 |
commit | 1bc5aee63eb72b341f506ad058502cd0361f0d10 (patch) | |
tree | c607e8252f3405424ff15bc2d00aa38dadbb2518 /gcc-4.9/gcc/testsuite/gcc.dg/tree-ssa/pr19210-1.c | |
parent | 283a0bf58fcf333c58a2a92c3ebbc41fb9eb1fdb (diff) | |
download | toolchain_gcc-1bc5aee63eb72b341f506ad058502cd0361f0d10.tar.gz toolchain_gcc-1bc5aee63eb72b341f506ad058502cd0361f0d10.tar.bz2 toolchain_gcc-1bc5aee63eb72b341f506ad058502cd0361f0d10.zip |
Initial checkin of GCC 4.9.0 from trunk (r208799).
Change-Id: I48a3c08bb98542aa215912a75f03c0890e497dba
Diffstat (limited to 'gcc-4.9/gcc/testsuite/gcc.dg/tree-ssa/pr19210-1.c')
-rw-r--r-- | gcc-4.9/gcc/testsuite/gcc.dg/tree-ssa/pr19210-1.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/gcc-4.9/gcc/testsuite/gcc.dg/tree-ssa/pr19210-1.c b/gcc-4.9/gcc/testsuite/gcc.dg/tree-ssa/pr19210-1.c new file mode 100644 index 000000000..906132c69 --- /dev/null +++ b/gcc-4.9/gcc/testsuite/gcc.dg/tree-ssa/pr19210-1.c @@ -0,0 +1,29 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -Wunsafe-loop-optimizations" } */ +extern void g(void); + +void +f (unsigned n) +{ + unsigned k; + for(k = 0;k <= n;k++) /* { dg-warning "cannot optimize.*infinite loops" } */ + g(); + + for(k = 0;k <= n;k += 4) /* { dg-warning "cannot optimize.*overflow" } */ + g(); + + /* We used to get warning for this loop. However, since then # of iterations + analysis improved, and we can now prove that this loop does not verflow. + This is because the only case when it would overflow is if n = ~0 (since + ~0 is divisible by 5), and this cannot be the case, since when we got + here, the previous loop exited, thus there exists k > n. */ + for(k = 5;k <= n;k += 5) + g(); + + /* So we need the following loop, instead. */ + for(k = 4;k <= n;k += 5) /* { dg-warning "cannot optimize.*overflow" } */ + g(); + + for(k = 15;k >= n;k--) /* { dg-warning "cannot optimize.*infinite" } */ + g(); +} |