GlobalOpt can't see through PHI nodes when doing SROA on malloc's

[llvmbot]

Bugzilla Link	1639
Resolution	FIXED
Resolved on	Sep 13, 2007 16:34
Version	trunk
OS	All
Attachments	gvn-out.bc
Reporter	LLVM Bugzilla Contributor

Extended Description

GlobalOpt, when it tries to do SROA on malloc's, must ensure that all uses of the global would trap if the global were null. This check, however, cannot see through PHI nodes, which causes a regression on 179.art when using GVN. Attached is the example bitcode. Note that GlobalOpt fails to SROA the global variable f1_layer because of the instruction %tmp11.rle in init_net().

[llvmbot]

assigned to @lattner

[lattner]

Fixed, patches here:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20070910/053491.html
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20070910/053492.html
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20070910/053493.html
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20070910/053494.html
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20070910/053495.html

This speeds 179.art up from 7.84s to 3.13s on PPC.
-Chris