Re: Fix tree-ssa-strlen handling of partial clobber (PR85814)

2018-05-21 Thread Jeff Law
On 05/18/2018 02:09 AM, Richard Sandiford wrote: > In this PR we have: > > c_5 = c_4(D) + 4; > c_12 = c_5 + 1; > *c_5 = 2; > a = 2; // A > c_21 = c_12 + 1; > *c_12 = 2; > a = 2; // B > c_28 = c_21 + 1; > *c_21 = 2; > a = 2; > c_7 = c_28 + 1; > *c_2

Fix tree-ssa-strlen handling of partial clobber (PR85814)

2018-05-18 Thread Richard Sandiford
In this PR we have: c_5 = c_4(D) + 4; c_12 = c_5 + 1; *c_5 = 2; a = 2;// A c_21 = c_12 + 1; *c_12 = 2; a = 2;// B c_28 = c_21 + 1; *c_21 = 2; a = 2; c_7 = c_28 + 1; *c_28 = 2; where a is a global int. We decide that A can't clobber *c_5 ==