On 5/24/19 12:27 AM, Eric Botcazou wrote:
There are a couple of testcases in the testsuite that, I believe, require a minimal form of support for symbolic ranges: gcc.dg/tree-ssa/vrp94.c and gnat.dg/opt40.adb. They deal with the following pattern in C:if (x >= y) return 1; z = y - x; if (z <= 0) abort (); return z; where we want to eliminate the abort. Of course the C version doesn't really make sense on its own, but it's the translation of the Ada version where the if (z <= 0) abort (); is generated by the compiler (it's a range check in Ada parlance).
I bet compiling anything Fortran-y with array bound checking on (-fbounds-check) would generate ginormous numbers of opportunities for symbolic range checking ...
-- Toon Moene - e-mail: t...@moene.org - phone: +31 346 214290 Saturnushof 14, 3738 XG Maartensdijk, The Netherlands At home: http://moene.org/~toon/; weather: http://moene.org/~hirlam/ Progress of GNU Fortran: http://gcc.gnu.org/wiki/GFortran#news
