diff options
| author | Benjamin Kramer <benny.kra@googlemail.com> | 2010-11-23 20:33:57 +0000 |
|---|---|---|
| committer | Benjamin Kramer <benny.kra@googlemail.com> | 2010-11-23 20:33:57 +0000 |
| commit | c21a821e9f044004bc504dd7bfdfaecb9d4af16b (patch) | |
| tree | e01a80c5fdfbe1e0a146ff48666d071091f90c62 /lib/Target/README.txt | |
| parent | b6133d148312a3ec15beb67c2f49a21e5082b666 (diff) | |
| download | llvm-c21a821e9f044004bc504dd7bfdfaecb9d4af16b.tar.gz llvm-c21a821e9f044004bc504dd7bfdfaecb9d4af16b.tar.bz2 llvm-c21a821e9f044004bc504dd7bfdfaecb9d4af16b.tar.xz | |
The srem -> urem transform is not safe for any divisor that's not a power of two.
E.g. -5 % 5 is 0 with srem and 1 with urem.
Also addresses Frits van Bommel's comments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120049 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/README.txt')
| -rw-r--r-- | lib/Target/README.txt | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/lib/Target/README.txt b/lib/Target/README.txt index b98531ca85..38f5af642d 100644 --- a/lib/Target/README.txt +++ b/lib/Target/README.txt @@ -1704,8 +1704,8 @@ Missed instcombine transformation: %384 = shl i64 %381, %383 ; [#uses=1] %385 = icmp slt i32 %tmp14.i, 64 ; [#uses=1] -The srem can be transformed to an and because if x is negative, the shift is -undefined. Testcase derived from 403.gcc. +The srem can be transformed to an and because if %tmp14.i is negative, the +shift is undefined. Testcase derived from 403.gcc. //===---------------------------------------------------------------------===// |