3 Commits

Author	SHA1	Message	Date
Bob Wilson	01e8d35855	Last week we were generating code with duplicate induction variables in this ... test, but the problem seems to have gone away today. Add a check to make sure it doesn't come back. llvm-svn: 96277	2010-02-15 21:56:40 +00:00
Bob Wilson	5d66f81412	Besides removing phi cycles that reduce to a single value, also remove dead ... phi cycles. Adjust a few tests to keep dead instructions from being optimized away. This (together with my previous change for phi cycles) fixes Apple radar 7627077. llvm-svn: 96057	2010-02-13 00:31:44 +00:00
Bob Wilson	2fd80c3d94	Add a new pass on machine instructions to optimize away PHI cycles that ... reduce down to a single value. InstCombine already does this transformation but DAG legalization may introduce new opportunities. This has turned out to be important for ARM where 64-bit values are split up during type legalization: InstCombine is not able to remove the PHI cycles on the 64-bit values but the separate 32-bit values can be optimized. I measured the compile time impact of this (running llc on 176.gcc) and it was not significant. llvm-svn: 95951	2010-02-12 01:30:21 +00:00