Bernd Schmidt writes: > On 09/16/2016 09:02 PM, Senthil Kumar Selvaraj wrote: >> Does this make sense? I ran a reg test for the avr target with a >> slightly older version of this patch, it did not show any regressions. >> If this is the right fix, I'll make sure to run reg tests on x86_64 >> after backporting to a gcc version where that target used reload. > > It's hard to say, and could have different effects on different targets. > One thing though, at the very least the reg_class_size test would have > to be adapted - the idea is to find the largest class, and there's a > risk here of ending up with a large class that only has one valid register.
Agreed - I've updated the patch to compute rclass sizes based on regno availability i.e., only if in_hard_reg_set_p and HARD_REGNO_MODE_OK, and then use the computed sizes when calculating best_size. > > You'll also want to verify this against > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54814 Yes, this patch doesn't break the fix for PR54814. The change to in_hard_reg_set_p was what fixed that, and that remains unmodified. Reg tested this on top of trunk@190252 with the in_hard_reg_set_p backport. x86_64-pc-linux bootstrapped and regtested ok. avr showed no regressions either. Ok for trunk? Regards Senthil gcc/ChangeLog: 2016-10-13 Senthil Kumar Selvaraj <senthil_kumar.selva...@atmel.com> * reload.c (find_valid_class_1): Allow regclass if atleast one regno in class is ok. Compute and use rclass size based on actually available regnos for mode in rclass. gcc/testsuite/ChangeLog: 2016-10-13 Senthil Kumar Selvaraj <senthil_kumar.selva...@atmel.com> * gcc.target/avr/pr71627.c: New. Index: gcc/reload.c =================================================================== --- gcc/reload.c (revision 240989) +++ gcc/reload.c (working copy) @@ -711,31 +711,36 @@ enum reg_class best_class = NO_REGS; unsigned int best_size = 0; int cost; + unsigned int computed_rclass_sizes[N_REG_CLASSES] = { 0 }; for (rclass = 1; rclass < N_REG_CLASSES; rclass++) { - int bad = 0; - for (regno = 0; regno < FIRST_PSEUDO_REGISTER && !bad; regno++) - { - if (in_hard_reg_set_p (reg_class_contents[rclass], mode, regno) - && !HARD_REGNO_MODE_OK (regno, mode)) - bad = 1; - } - - if (bad) - continue; + int atleast_one_regno_ok = 0; + for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) + { + if (in_hard_reg_set_p (reg_class_contents[rclass], mode, regno)) + { + atleast_one_regno_ok = 1; + if (HARD_REGNO_MODE_OK (regno, mode)) + computed_rclass_sizes[rclass]++; + } + } + + if (!atleast_one_regno_ok) + continue; + cost = register_move_cost (outer, (enum reg_class) rclass, dest_class); - if ((reg_class_size[rclass] > best_size - && (best_cost < 0 || best_cost >= cost)) - || best_cost > cost) - { - best_class = (enum reg_class) rclass; - best_size = reg_class_size[rclass]; - best_cost = register_move_cost (outer, (enum reg_class) rclass, - dest_class); - } + if ((computed_rclass_sizes[rclass] > best_size + && (best_cost < 0 || best_cost >= cost)) + || best_cost > cost) + { + best_class = (enum reg_class) rclass; + best_size = computed_rclass_sizes[rclass]; + best_cost = register_move_cost (outer, (enum reg_class) rclass, + dest_class); + } } gcc_assert (best_size != 0); Index: gcc/testsuite/gcc.target/avr/pr71627.c =================================================================== --- gcc/testsuite/gcc.target/avr/pr71627.c (nonexistent) +++ gcc/testsuite/gcc.target/avr/pr71627.c (working copy) @@ -0,0 +1,14 @@ +/* { dg-do compile } */ +/* { dg-options "-O1" } */ + + +extern volatile __memx const long a, b, c, d, e, f; +extern volatile long result; + +extern void vfunc (const char*, ...); + +void foo (void) +{ + result = a + b + c + d + e + f; + vfunc ("text", a, b, c, d, e, f, result); +}
