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[Bug tree-optimization/25881] unsigned int loop indices don't optimize as good as int or __SIZE_TYPE__ for 64bit targets
- From: "irar at il dot ibm dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 29 Jan 2006 10:10:56 -0000
- Subject: [Bug tree-optimization/25881] unsigned int loop indices don't optimize as good as int or __SIZE_TYPE__ for 64bit targets
- References: <bug-25881-11859@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #2 from irar at il dot ibm dot com 2006-01-29 10:10 -------
Changing double to float, the scalar evolution analyzer returns access function
(float *) ((unsigned int) {0, +, 1}_1 * 4) + (float *) a_12,
since it fails in type conversion:
(failed conversion:
type: unsigned int
base: 0
step:
estimated_nb_iterations: scev_not_known
)
(Without type conversion we get {(float *) a_14, +, 4B}_1).
Data-refs analysis fails to analyze the access pattern, therefore the loop does
not get vectorized.
--
irar at il dot ibm dot com changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |sebastian dot pop at cri dot
| |ensmp dot fr, irar at il dot
| |ibm dot com
Last reconfirmed|2006-01-20 20:43:27 |2006-01-29 10:10:55
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25881