------- Comment #8 from ebotcazou at gcc dot gnu dot org 2008-02-12 08:45 ------- The failure mode is as follows: IVOPTS decices to turn the iteration on the value of A (variable in the code) to an iteration on its address. But there is a cast in the middle
a.0_4 = (system__aux_dec__TsaB) a_3(D); D.249_5 = i_131 + a.0_4; so create_iv invokes force_gimple_operand on ADDR_EXPR<NOP_EXPR<SSA_NAME>>, which is passed to gnat_gimplify_expr. The latter creates the temporary A.36 and it is never marked for renaming. I think that the problem is in create_iv: it should make sure that the SSA form is preserved, for example by invoking force_gimple_operand_bsi instead of force_gimple_operand like some functions in tree-ssa-loop-ivopts.c. But maybe the problem is the discrepancy between force_gimple_operand and force_gimple_operand_bsi: why does the latter preserve the SSA form and not the former? -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35136
