diff options
Diffstat (limited to 'lib/Target/README.txt')
-rw-r--r-- | lib/Target/README.txt | 12 |
1 files changed, 2 insertions, 10 deletions
diff --git a/lib/Target/README.txt b/lib/Target/README.txt index 4d5b17ab36..b98531ca85 100644 --- a/lib/Target/README.txt +++ b/lib/Target/README.txt @@ -1698,22 +1698,14 @@ from gcc. //===---------------------------------------------------------------------===// Missed instcombine transformation: -define i32 @a(i32 %x) nounwind readnone { -entry: - %rem = srem i32 %x, 32 - %shl = shl i32 1, %rem - ret i32 %shl -} - -The srem can be transformed to an and because if x is negative, the shift is -undefined. Here's a more general case that occurs on 64-bit targets: %382 = srem i32 %tmp14.i, 64 ; [#uses=1] %383 = zext i32 %382 to i64 ; [#uses=1] %384 = shl i64 %381, %383 ; [#uses=1] %385 = icmp slt i32 %tmp14.i, 64 ; [#uses=1] -Testcase derived from 403.gcc. +The srem can be transformed to an and because if x is negative, the shift is +undefined. Testcase derived from 403.gcc. //===---------------------------------------------------------------------===// |