On 2016.10.18 at 08:15 -0500, Bill Schmidt wrote: > On Tue, 2016-10-18 at 05:13 +0200, Markus Trippelsdorf wrote: > > On 2016.10.17 at 17:23 -0500, Bill Schmidt wrote: > > > Hi, > > > > > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77916 identifies a situation > > > where SLSR will ICE when exposed to a cast from integer to pointer. This > > > is because we try to convert a PLUS_EXPR with an addend of -1 * S into a > > > MINUS_EXPR with a subtrahend of S, but the base operand is unexpectedly > > > of pointer type. This patch recognizes when pointer arithmetic is taking > > > place and ensures that we use a POINTER_PLUS_EXPR at all such times. In > > > the case of the PR, this occurs in the logic where the stride S is a known > > > constant value, but the same problem could occur when it is an SSA_NAME > > > without known value. Both possibilities are handled here. > > > > > > Fixing the code to ensure that the unknown stride case always uses an > > > initializer for a negative increment allows us to remove the stopgap fix > > > added for PR77937 as well. > > > > > > Bootstrapped and tested on powerpc64le-unknown-linux-gnu with no > > > regressions, committed. > > > > Perhaps you should consider building ffmpeg with -O3 -march=amdfam10 on > > X86_64 before committing these patches, because you broke it for the > > third time in the last couple of days. > > Sorry, sorry. I did intend to build another stage1 cross and try this, > but it just slipped my mind. Looks like I'll need to put the stopgap > fix back in. I'll do that shortly. > > Meantime, -fno-slsr is a workaround. If I have trouble building ffmpeg > with a cross, I'll check with you on testing a future patch.
I you wish I can send you a tarball with the preprocessed *.i files from ffmpeg, so that you can use a stage1 cross on them. -- Markus
