| Message ID | 20160817182636.GA16702@intel.com |
|---|---|
| State | New |
| Headers | show |
On Wed, Aug 17, 2016 at 8:26 PM, H.J. Lu <hongjiu.lu@intel.com> wrote: > Larger MOVE_RATIO will always make code faster. 17 is the number with > smaller code sizes for Lakemont. > > Tested on x86-64. OK for trunk? OK, I assume that the patch is based on some benchmark. Thanks, Uros. > > H.J. > --- > gcc/ > > PR target/72839 > * config/i386/i386.c (lakemont_cost): Set MOVE_RATIO to 17. > > gcc/testsuite/ > > PR target/72839 > * gcc.target/i386/pr72839.c: New test. > --- > gcc/config/i386/i386.c | 2 +- > gcc/testsuite/gcc.target/i386/pr72839.c | 17 +++++++++++++++++ > 2 files changed, 18 insertions(+), 1 deletion(-) > create mode 100644 gcc/testsuite/gcc.target/i386/pr72839.c > > diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c > index 3805817..8fe3821 100644 > --- a/gcc/config/i386/i386.c > +++ b/gcc/config/i386/i386.c > @@ -426,7 +426,7 @@ struct processor_costs lakemont_cost = { > COSTS_N_INSNS (3), /* cost of movsx */ > COSTS_N_INSNS (2), /* cost of movzx */ > 8, /* "large" insn */ > - 9, /* MOVE_RATIO */ > + 17, /* MOVE_RATIO */ > 6, /* cost for loading QImode using movzbl */ > {2, 4, 2}, /* cost of loading integer registers > in QImode, HImode and SImode. > diff --git a/gcc/testsuite/gcc.target/i386/pr72839.c b/gcc/testsuite/gcc.target/i386/pr72839.c > new file mode 100644 > index 0000000..ea724f7 > --- /dev/null > +++ b/gcc/testsuite/gcc.target/i386/pr72839.c > @@ -0,0 +1,17 @@ > +/* { dg-do compile } */ > +/* { dg-require-effective-target ia32 } */ > +/* { dg-options "-O2 -mtune=lakemont" } */ > + > +extern char *strcpy (char *, const char *); > + > +void > +foo (char *s) > +{ > + strcpy (s, > + "12345678123456781234567812345678123456781234567812345678" > + "1234567"); > +} > + > +/* { dg-final { scan-assembler-times "movl\[ \\t\]+\\$\[0-9\]+, \[0-9\]*\\(%\[^,\]+\\)" 16 } } */ > +/* { dg-final { scan-assembler-not "rep movsl" } } */ > +/* { dg-final { scan-assembler-not "rep movsb" } } */ > -- > 2.7.4 >
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c index 3805817..8fe3821 100644 --- a/gcc/config/i386/i386.c +++ b/gcc/config/i386/i386.c @@ -426,7 +426,7 @@ struct processor_costs lakemont_cost = { COSTS_N_INSNS (3), /* cost of movsx */ COSTS_N_INSNS (2), /* cost of movzx */ 8, /* "large" insn */ - 9, /* MOVE_RATIO */ + 17, /* MOVE_RATIO */ 6, /* cost for loading QImode using movzbl */ {2, 4, 2}, /* cost of loading integer registers in QImode, HImode and SImode. diff --git a/gcc/testsuite/gcc.target/i386/pr72839.c b/gcc/testsuite/gcc.target/i386/pr72839.c new file mode 100644 index 0000000..ea724f7 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr72839.c @@ -0,0 +1,17 @@ +/* { dg-do compile } */ +/* { dg-require-effective-target ia32 } */ +/* { dg-options "-O2 -mtune=lakemont" } */ + +extern char *strcpy (char *, const char *); + +void +foo (char *s) +{ + strcpy (s, + "12345678123456781234567812345678123456781234567812345678" + "1234567"); +} + +/* { dg-final { scan-assembler-times "movl\[ \\t\]+\\$\[0-9\]+, \[0-9\]*\\(%\[^,\]+\\)" 16 } } */ +/* { dg-final { scan-assembler-not "rep movsl" } } */ +/* { dg-final { scan-assembler-not "rep movsb" } } */