Message ID | 20211111194116.1626980-2-siddhesh@gotplt.org |
---|---|
State | New |
Headers | show |
Series | gimple-fold improvements | expand |
On Fri, 12 Nov 2021 at 01:12, Siddhesh Poyarekar <siddhesh@gotplt.org> wrote: > > Avoid going through another folding cycle and use the ignore flag to > directly transform BUILT_IN_STPCPY_CHK to BUILT_IN_STRCPY when set, > likewise for BUILT_IN_STPNCPY_CHK to BUILT_IN_STPNCPY. > > Dump the transformation in dump_file so that we can verify in tests that > the direct transformation actually happened. > > gcc/ChangeLog: > > * gimple-fold.c (gimple_fold_builtin_stxcpy_chk, > gimple_fold_builtin_stxncpy_chk): Use BUILT_IN_STRNCPY if return > value is not used. > > gcc/testsuite/ChangeLog: > > * gcc.dg/fold-stringops.c: New test. > > Signed-off-by: Siddhesh Poyarekar <siddhesh@gotplt.org> > --- > gcc/gimple-fold.c | 50 +++++++++++++++++-------- > gcc/testsuite/gcc.dg/fold-stringops-1.c | 23 ++++++++++++ > 2 files changed, 57 insertions(+), 16 deletions(-) > create mode 100644 gcc/testsuite/gcc.dg/fold-stringops-1.c > > diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c > index 6e25a7c05db..92e15784803 100644 > --- a/gcc/gimple-fold.c > +++ b/gcc/gimple-fold.c > @@ -3088,6 +3088,19 @@ gimple_fold_builtin_memory_chk (gimple_stmt_iterator *gsi, > return true; > } > > +static void > +dump_transformation (gimple *from, gimple *to) I assume that both from and to will always be builtin calls ? In that case, perhaps better to use gcall * here (and in rest of patch). Also, needs a top-level comment describing the function. > +{ > + if (dump_file && (dump_flags & TDF_DETAILS)) Perhaps better to use dump_enabled_p ? > + { > + fprintf (dump_file, "transformed "); Perhaps use dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, ...) ? I think you can use gimple_location to get the location. Thanks, Prathamesh > + print_generic_expr (dump_file, gimple_call_fn (from), dump_flags); > + fprintf (dump_file, " to "); > + print_generic_expr (dump_file, gimple_call_fn (to), dump_flags); > + fprintf (dump_file, "\n"); > + } > +} > + > /* Fold a call to the __st[rp]cpy_chk builtin. > DEST, SRC, and SIZE are the arguments to the call. > IGNORE is true if return value can be ignored. FCODE is the BUILT_IN_* > @@ -3184,12 +3197,13 @@ gimple_fold_builtin_stxcpy_chk (gimple_stmt_iterator *gsi, > } > > /* If __builtin_st{r,p}cpy_chk is used, assume st{r,p}cpy is available. */ > - fn = builtin_decl_explicit (fcode == BUILT_IN_STPCPY_CHK > + fn = builtin_decl_explicit (fcode == BUILT_IN_STPCPY_CHK && !ignore > ? BUILT_IN_STPCPY : BUILT_IN_STRCPY); > if (!fn) > return false; > > gimple *repl = gimple_build_call (fn, 2, dest, src); > + dump_transformation (stmt, repl); > replace_call_with_call_and_fold (gsi, repl); > return true; > } > @@ -3209,19 +3223,6 @@ gimple_fold_builtin_stxncpy_chk (gimple_stmt_iterator *gsi, > bool ignore = gimple_call_lhs (stmt) == NULL_TREE; > tree fn; > > - if (fcode == BUILT_IN_STPNCPY_CHK && ignore) > - { > - /* If return value of __stpncpy_chk is ignored, > - optimize into __strncpy_chk. */ > - fn = builtin_decl_explicit (BUILT_IN_STRNCPY_CHK); > - if (fn) > - { > - gimple *repl = gimple_build_call (fn, 4, dest, src, len, size); > - replace_call_with_call_and_fold (gsi, repl); > - return true; > - } > - } > - > if (! tree_fits_uhwi_p (size)) > return false; > > @@ -3234,7 +3235,23 @@ gimple_fold_builtin_stxncpy_chk (gimple_stmt_iterator *gsi, > For MAXLEN only allow optimizing into non-_ocs function > if SIZE is >= MAXLEN, never convert to __ocs_fail (). */ > if (maxlen == NULL_TREE || ! tree_fits_uhwi_p (maxlen)) > - return false; > + { > + if (fcode == BUILT_IN_STPNCPY_CHK && ignore) > + { > + /* If return value of __stpncpy_chk is ignored, > + optimize into __strncpy_chk. */ > + fn = builtin_decl_explicit (BUILT_IN_STRNCPY_CHK); > + if (fn) > + { > + gimple *repl = gimple_build_call (fn, 4, dest, src, len, > + size); > + replace_call_with_call_and_fold (gsi, repl); > + return true; > + } > + } > + > + return false; > + } > } > else > maxlen = len; > @@ -3244,12 +3261,13 @@ gimple_fold_builtin_stxncpy_chk (gimple_stmt_iterator *gsi, > } > > /* If __builtin_st{r,p}ncpy_chk is used, assume st{r,p}ncpy is available. */ > - fn = builtin_decl_explicit (fcode == BUILT_IN_STPNCPY_CHK > + fn = builtin_decl_explicit (fcode == BUILT_IN_STPNCPY_CHK && !ignore > ? BUILT_IN_STPNCPY : BUILT_IN_STRNCPY); > if (!fn) > return false; > > gimple *repl = gimple_build_call (fn, 3, dest, src, len); > + dump_transformation (stmt, repl); > replace_call_with_call_and_fold (gsi, repl); > return true; > } > diff --git a/gcc/testsuite/gcc.dg/fold-stringops-1.c b/gcc/testsuite/gcc.dg/fold-stringops-1.c > new file mode 100644 > index 00000000000..712dd369e7c > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/fold-stringops-1.c > @@ -0,0 +1,23 @@ > +/* { dg-do compile } */ > +/* { dg-options "-O2 -fdump-tree-lower-details" } */ > + > +char dst[2048]; > + > +char * > +copy1 (const char *src, int cond) > +{ > + __builtin___stpncpy_chk (dst, src, 42, __builtin_object_size (dst, 0)); > + > + return dst; > +} > + > +char * > +copy2 (void) > +{ > + __builtin___stpcpy_chk (dst, "Hello world", __builtin_object_size (dst, 0)); > + > + return dst; > +} > +/* { dg-final { scan-tree-dump "transformed __builtin___stpncpy_chk to __builtin_strncpy" "lower" } } */ > +/* { dg-final { scan-tree-dump "transformed __builtin___stpcpy_chk to __builtin_strcpy" "lower" } } */ > + > -- > 2.31.1 >
On 11/12/21 22:46, Prathamesh Kulkarni wrote: > On Fri, 12 Nov 2021 at 01:12, Siddhesh Poyarekar <siddhesh@gotplt.org> wrote: >> >> Avoid going through another folding cycle and use the ignore flag to >> directly transform BUILT_IN_STPCPY_CHK to BUILT_IN_STRCPY when set, >> likewise for BUILT_IN_STPNCPY_CHK to BUILT_IN_STPNCPY. >> >> Dump the transformation in dump_file so that we can verify in tests that >> the direct transformation actually happened. >> >> gcc/ChangeLog: >> >> * gimple-fold.c (gimple_fold_builtin_stxcpy_chk, >> gimple_fold_builtin_stxncpy_chk): Use BUILT_IN_STRNCPY if return >> value is not used. >> >> gcc/testsuite/ChangeLog: >> >> * gcc.dg/fold-stringops.c: New test. >> >> Signed-off-by: Siddhesh Poyarekar <siddhesh@gotplt.org> >> --- >> gcc/gimple-fold.c | 50 +++++++++++++++++-------- >> gcc/testsuite/gcc.dg/fold-stringops-1.c | 23 ++++++++++++ >> 2 files changed, 57 insertions(+), 16 deletions(-) >> create mode 100644 gcc/testsuite/gcc.dg/fold-stringops-1.c >> >> diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c >> index 6e25a7c05db..92e15784803 100644 >> --- a/gcc/gimple-fold.c >> +++ b/gcc/gimple-fold.c >> @@ -3088,6 +3088,19 @@ gimple_fold_builtin_memory_chk (gimple_stmt_iterator *gsi, >> return true; >> } >> >> +static void >> +dump_transformation (gimple *from, gimple *to) > I assume that both from and to will always be builtin calls ? > In that case, perhaps better to use gcall * here (and in rest of patch). > Also, needs a top-level comment describing the function. >> +{ >> + if (dump_file && (dump_flags & TDF_DETAILS)) > Perhaps better to use dump_enabled_p ? >> + { >> + fprintf (dump_file, "transformed "); > Perhaps use dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, ...) ? > I think you can use gimple_location to get the location. > Thanks, I'll fix these up. Siddhesh
diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c index 6e25a7c05db..92e15784803 100644 --- a/gcc/gimple-fold.c +++ b/gcc/gimple-fold.c @@ -3088,6 +3088,19 @@ gimple_fold_builtin_memory_chk (gimple_stmt_iterator *gsi, return true; } +static void +dump_transformation (gimple *from, gimple *to) +{ + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "transformed "); + print_generic_expr (dump_file, gimple_call_fn (from), dump_flags); + fprintf (dump_file, " to "); + print_generic_expr (dump_file, gimple_call_fn (to), dump_flags); + fprintf (dump_file, "\n"); + } +} + /* Fold a call to the __st[rp]cpy_chk builtin. DEST, SRC, and SIZE are the arguments to the call. IGNORE is true if return value can be ignored. FCODE is the BUILT_IN_* @@ -3184,12 +3197,13 @@ gimple_fold_builtin_stxcpy_chk (gimple_stmt_iterator *gsi, } /* If __builtin_st{r,p}cpy_chk is used, assume st{r,p}cpy is available. */ - fn = builtin_decl_explicit (fcode == BUILT_IN_STPCPY_CHK + fn = builtin_decl_explicit (fcode == BUILT_IN_STPCPY_CHK && !ignore ? BUILT_IN_STPCPY : BUILT_IN_STRCPY); if (!fn) return false; gimple *repl = gimple_build_call (fn, 2, dest, src); + dump_transformation (stmt, repl); replace_call_with_call_and_fold (gsi, repl); return true; } @@ -3209,19 +3223,6 @@ gimple_fold_builtin_stxncpy_chk (gimple_stmt_iterator *gsi, bool ignore = gimple_call_lhs (stmt) == NULL_TREE; tree fn; - if (fcode == BUILT_IN_STPNCPY_CHK && ignore) - { - /* If return value of __stpncpy_chk is ignored, - optimize into __strncpy_chk. */ - fn = builtin_decl_explicit (BUILT_IN_STRNCPY_CHK); - if (fn) - { - gimple *repl = gimple_build_call (fn, 4, dest, src, len, size); - replace_call_with_call_and_fold (gsi, repl); - return true; - } - } - if (! tree_fits_uhwi_p (size)) return false; @@ -3234,7 +3235,23 @@ gimple_fold_builtin_stxncpy_chk (gimple_stmt_iterator *gsi, For MAXLEN only allow optimizing into non-_ocs function if SIZE is >= MAXLEN, never convert to __ocs_fail (). */ if (maxlen == NULL_TREE || ! tree_fits_uhwi_p (maxlen)) - return false; + { + if (fcode == BUILT_IN_STPNCPY_CHK && ignore) + { + /* If return value of __stpncpy_chk is ignored, + optimize into __strncpy_chk. */ + fn = builtin_decl_explicit (BUILT_IN_STRNCPY_CHK); + if (fn) + { + gimple *repl = gimple_build_call (fn, 4, dest, src, len, + size); + replace_call_with_call_and_fold (gsi, repl); + return true; + } + } + + return false; + } } else maxlen = len; @@ -3244,12 +3261,13 @@ gimple_fold_builtin_stxncpy_chk (gimple_stmt_iterator *gsi, } /* If __builtin_st{r,p}ncpy_chk is used, assume st{r,p}ncpy is available. */ - fn = builtin_decl_explicit (fcode == BUILT_IN_STPNCPY_CHK + fn = builtin_decl_explicit (fcode == BUILT_IN_STPNCPY_CHK && !ignore ? BUILT_IN_STPNCPY : BUILT_IN_STRNCPY); if (!fn) return false; gimple *repl = gimple_build_call (fn, 3, dest, src, len); + dump_transformation (stmt, repl); replace_call_with_call_and_fold (gsi, repl); return true; } diff --git a/gcc/testsuite/gcc.dg/fold-stringops-1.c b/gcc/testsuite/gcc.dg/fold-stringops-1.c new file mode 100644 index 00000000000..712dd369e7c --- /dev/null +++ b/gcc/testsuite/gcc.dg/fold-stringops-1.c @@ -0,0 +1,23 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-lower-details" } */ + +char dst[2048]; + +char * +copy1 (const char *src, int cond) +{ + __builtin___stpncpy_chk (dst, src, 42, __builtin_object_size (dst, 0)); + + return dst; +} + +char * +copy2 (void) +{ + __builtin___stpcpy_chk (dst, "Hello world", __builtin_object_size (dst, 0)); + + return dst; +} +/* { dg-final { scan-tree-dump "transformed __builtin___stpncpy_chk to __builtin_strncpy" "lower" } } */ +/* { dg-final { scan-tree-dump "transformed __builtin___stpcpy_chk to __builtin_strcpy" "lower" } } */ +
Avoid going through another folding cycle and use the ignore flag to directly transform BUILT_IN_STPCPY_CHK to BUILT_IN_STRCPY when set, likewise for BUILT_IN_STPNCPY_CHK to BUILT_IN_STPNCPY. Dump the transformation in dump_file so that we can verify in tests that the direct transformation actually happened. gcc/ChangeLog: * gimple-fold.c (gimple_fold_builtin_stxcpy_chk, gimple_fold_builtin_stxncpy_chk): Use BUILT_IN_STRNCPY if return value is not used. gcc/testsuite/ChangeLog: * gcc.dg/fold-stringops.c: New test. Signed-off-by: Siddhesh Poyarekar <siddhesh@gotplt.org> --- gcc/gimple-fold.c | 50 +++++++++++++++++-------- gcc/testsuite/gcc.dg/fold-stringops-1.c | 23 ++++++++++++ 2 files changed, 57 insertions(+), 16 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/fold-stringops-1.c