A new test is added: gcc/testsuite/ChangeLog:
2014-01-24 Dehao Chen <[email protected]> * gcc.dg/predict-8.c: New test. Index: gcc/testsuite/gcc.dg/predict-8.c =================================================================== --- gcc/testsuite/gcc.dg/predict-8.c (revision 0) +++ gcc/testsuite/gcc.dg/predict-8.c (revision 0) @@ -0,0 +1,12 @@ +/* { dg-do compile { target { x86_64-*-* } } } */ +/* { dg-options "-O2 -fdump-rtl-expand -c" } */ + +int foo(float a, float b) { + if (a == b) + return 1; + else + return 2; +} + +/* { dg-final { scan-rtl-dump-times "REG_BR_PROB 100" 1 "expand"} } */ +/* { dg-final { cleanup-rtl-dump "expand" } } */ On Thu, Jan 23, 2014 at 4:30 PM, Xinliang David Li <[email protected]> wrote: > Is it possible to add a test case? > > David > > On Wed, Jan 22, 2014 at 6:08 PM, Dehao Chen <[email protected]> wrote: >> During floating point comparison, compiler inserts conditional jumps >> to check if the operand is NAN. These type of checks are normally >> false. However, compiler sets the probability the same as the original >> float-compare conditional jump. This patch sets the probability of >> these conditional jumps as 1%. >> >> Bootstrapped and passed regression test. >> >> OK for trunk? >> >> Thanks, >> Dehao >> >> gcc/ChangeLog: >> 2014-01-22 Dehao Chen <[email protected]> >> >> * dojump.c (do_compare_rtx_and_jump): Sets correct probability for >> compiler inserted conditional jumps for NAN float check. >> >> Index: gcc/dojump.c >> =================================================================== >> --- gcc/dojump.c (revision 206945) >> +++ gcc/dojump.c (working copy) >> @@ -1103,6 +1103,11 @@ do_compare_rtx_and_jump (rtx op0, rtx op1, enum rt >> >> else >> { >> + int first_prob = prob; >> + if (first_code == UNORDERED) >> + first_prob = REG_BR_PROB_BASE / 100; >> + else if (first_code == ORDERED) >> + first_prob = REG_BR_PROB_BASE - REG_BR_PROB_BASE / 100; >> if (and_them) >> { >> rtx dest_label; >> @@ -1116,11 +1121,13 @@ do_compare_rtx_and_jump (rtx op0, rtx op1, enum rt >> else >> dest_label = if_false_label; >> do_compare_rtx_and_jump (op0, op1, first_code, >> unsignedp, mode, >> - size, dest_label, NULL_RTX, prob); >> + size, dest_label, NULL_RTX, >> + first_prob); >> } >> else >> do_compare_rtx_and_jump (op0, op1, first_code, unsignedp, >> mode, >> - size, NULL_RTX, if_true_label, prob); >> + size, NULL_RTX, if_true_label, >> + first_prob); >> } >> }
