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------------------------------------------------------------------------ r198290 | aschwaighofer | 2014-01-01 22:31:36 -0500 (Wed, 01 Jan 2014) | 23 lines BasicAA: Fix value equality and phi cycles When there are cycles in the value graph we have to be careful interpreting "Value*" identity as "value" equivalence. We interpret the value of a phi node as the value of its operands. When we check for value equivalence now we make sure that the "Value*" dominates all cycles (phis). %0 = phi [%noaliasval, %addr2] %l = load %ptr %addr1 = gep @a, 0, %l %addr2 = gep @a, 0, (%l + 1) store %ptr ... Before this patch we would return NoAlias for (%0, %addr1) which is wrong because the value of the load is from different iterations of the loop. Tested on x86_64 -mavx at O3 and O3 -flto with no performance or compile time regressions. PR18068 radar://15653794 ------------------------------------------------------------------------ git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_34@206051 91177308-0d34-0410-b5e6-96231b3b80d8