| Message ID | CAFULd4bKjA7ZHKtFSqP5izEZPT8=nMbreKk52YDJNH+Y6aAtcA@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
Index: config/i386/i386.c =================================================================== --- config/i386/i386.c (revision 183953) +++ config/i386/i386.c (working copy) @@ -17778,6 +17778,27 @@ ix86_cc_modes_compatible (enum machine_mode m1, en || (m1 == CCGOCmode && m2 == CCGCmode)) return CCGCmode; + if (m1 == CCZmode) + switch (m2) + { + default: + break; + case CCGOCmode: + case CCGCmode: + case CCNOmode: + return m2; + } + else if (m2 == CCZmode) + switch (m1) + { + default: + break; + case CCGOCmode: + case CCGCmode: + case CCNOmode: + return m1; + } + switch (m1) { default:
Hello! Attached patch declares CCZmode compatible with CCGOC, CCGO and CCNO modes. 2012-02-07 Uros Bizjak <ubizjak@gmail.com> * config/i386/i386.c (ix86_cc_modes_compatible): Declare CCZmode compatible with CCGOCmode, CCGCmode and CCNOmode. Bootstrapped on x86_64-pc-linux-gnu, regression test still in progress. This patch (together with previous combine/i386 proto-patch) is still not enough to remove redundant test instruction from int test (int a, int b) { int lt = a + b < 0; int eq = a + b == 0; if (lt) return 1; return eq; } It looks to me that something is wrong with compare-elim pass. Since CCZmode is now made compatible with CCGOCmode (and results in CCGOCmode), compare-elim pass should update the comparison mode in > (insn 9 8 10 2 (parallel [ > (set (reg:SI 5 di [orig:60 D.1710 ] [60]) > (plus:SI (reg/v:SI 5 di [orig:63 a ] [63]) > (reg/v:SI 4 si [orig:64 b ] [64]))) > (set (reg:CCZ 17 flags) > (compare:CCZ (plus:SI (reg/v:SI 5 di [orig:63 a ] [63]) > (reg/v:SI 4 si [orig:64 b ] [64])) > (const_int 0 [0]))) > ]) cmp.c:4 261 {*addsi_2} > (nil)) to CCGOCmode and eliminate CCGOC compare: > (insn 29 30 31 2 (set (reg:CCGOC 17 flags) > (compare:CCGOC (reg:SI 5 di [orig:60 D.1710 ] [60]) > (const_int 0 [0]))) cmp.c:6 2 {*cmpsi_ccno_1} > (nil)) Uros.