Implement pz2ind(), pind2sz(), and psz2u().

These compute size classes and indices similarly to size2index(),
index2size() and s2u(), respectively, but using the subset of size
classes that are multiples of the page size.  Note that pszind_t and
szind_t are not interchangeable.

3 files changed, 116 insertions, 13 deletions

diff --git a/include/jemalloc/internal/jemalloc_internal.h.in b/include/jemalloc/internal/jemalloc_internal.h.in
index 6a0aa00..76dff3f 100644
--- a/include/jemalloc/internal/jemalloc_internal.h.in
+++ b/include/jemalloc/internal/jemalloc_internal.h.in
@@ -187,6 +187,9 @@ static const bool config_cache_oblivious =
 
 #include "jemalloc/internal/jemalloc_internal_macros.h"
 
+/* Page size index type. */
+typedef unsigned pszind_t;
+
 /* Size class index type. */
 typedef unsigned szind_t;
 
@@ -545,6 +548,9 @@ void	jemalloc_postfork_child(void);
 #include "jemalloc/internal/huge.h"
 
 #ifndef JEMALLOC_ENABLE_INLINE
+pszind_t	psz2ind(size_t psz);
+size_t	pind2sz(pszind_t pind);
+size_t	psz2u(size_t psz);
 szind_t	size2index_compute(size_t size);
 szind_t	size2index_lookup(size_t size);
 szind_t	size2index(size_t size);
@@ -565,10 +571,74 @@ ticker_t	*decay_ticker_get(tsd_t *tsd, unsigned ind);
 #endif
 
 #if (defined(JEMALLOC_ENABLE_INLINE) || defined(JEMALLOC_C_))
+JEMALLOC_INLINE pszind_t
+psz2ind(size_t psz)
+{
+
+	if (unlikely(psz > HUGE_MAXCLASS))
+		return (NPSIZES);
+	{
+		pszind_t x = lg_floor((psz<<1)-1);
+		pszind_t shift = (x < LG_SIZE_CLASS_GROUP + LG_PAGE) ? 0 : x -
+		    (LG_SIZE_CLASS_GROUP + LG_PAGE);
+		pszind_t grp = shift << LG_SIZE_CLASS_GROUP;
+
+		pszind_t lg_delta = (x < LG_SIZE_CLASS_GROUP + LG_PAGE + 1) ?
+		    LG_PAGE : x - LG_SIZE_CLASS_GROUP - 1;
+
+		size_t delta_inverse_mask = ZI(-1) << lg_delta;
+		pszind_t mod = ((((psz-1) & delta_inverse_mask) >> lg_delta)) &
+		    ((ZU(1) << LG_SIZE_CLASS_GROUP) - 1);
+
+		pszind_t ind = grp + mod;
+		return (ind);
+	}
+}
+
+JEMALLOC_INLINE size_t
+pind2sz(pszind_t pind)
+{
+
+	{
+		size_t grp = pind >> LG_SIZE_CLASS_GROUP;
+		size_t mod = pind & ((ZU(1) << LG_SIZE_CLASS_GROUP) - 1);
+
+		size_t grp_size_mask = ~((!!grp)-1);
+		size_t grp_size = ((ZU(1) << (LG_PAGE +
+		    (LG_SIZE_CLASS_GROUP-1))) << grp) & grp_size_mask;
+
+		size_t shift = (grp == 0) ? 1 : grp;
+		size_t lg_delta = shift + (LG_PAGE-1);
+		size_t mod_size = (mod+1) << lg_delta;
+
+		size_t sz = grp_size + mod_size;
+		return (sz);
+	}
+}
+
+JEMALLOC_INLINE size_t
+psz2u(size_t psz)
+{
+
+	if (unlikely(psz > HUGE_MAXCLASS))
+		return (0);
+	{
+		size_t x = lg_floor((psz<<1)-1);
+		size_t lg_delta = (x < LG_SIZE_CLASS_GROUP + LG_PAGE + 1) ?
+		    LG_PAGE : x - LG_SIZE_CLASS_GROUP - 1;
+		size_t delta = ZU(1) << lg_delta;
+		size_t delta_mask = delta - 1;
+		size_t usize = (psz + delta_mask) & ~delta_mask;
+		return (usize);
+	}
+}
+
 JEMALLOC_INLINE szind_t
 size2index_compute(size_t size)
 {
 
+	if (unlikely(size > HUGE_MAXCLASS))
+		return (NSIZES);
 #if (NTBINS != 0)
 	if (size <= (ZU(1) << LG_TINY_MAXCLASS)) {
 		szind_t lg_tmin = LG_TINY_MAXCLASS - NTBINS + 1;
@@ -577,9 +647,7 @@ size2index_compute(size_t size)
 	}
 #endif
 	{
-		szind_t x = unlikely(ZI(size) < 0) ? ((size<<1) ?
-		    (ZU(1)<<(LG_SIZEOF_PTR+3)) : ((ZU(1)<<(LG_SIZEOF_PTR+3))-1))
-		    : lg_floor((size<<1)-1);
+		szind_t x = lg_floor((size<<1)-1);
 		szind_t shift = (x < LG_SIZE_CLASS_GROUP + LG_QUANTUM) ? 0 :
 		    x - (LG_SIZE_CLASS_GROUP + LG_QUANTUM);
 		szind_t grp = shift << LG_SIZE_CLASS_GROUP;
@@ -665,6 +733,8 @@ JEMALLOC_ALWAYS_INLINE size_t
 s2u_compute(size_t size)
 {
 
+	if (unlikely(size > HUGE_MAXCLASS))
+		return (0);
 #if (NTBINS > 0)
 	if (size <= (ZU(1) << LG_TINY_MAXCLASS)) {
 		size_t lg_tmin = LG_TINY_MAXCLASS - NTBINS + 1;
@@ -674,9 +744,7 @@ s2u_compute(size_t size)
 	}
 #endif
 	{
-		size_t x = unlikely(ZI(size) < 0) ? ((size<<1) ?
-		    (ZU(1)<<(LG_SIZEOF_PTR+3)) : ((ZU(1)<<(LG_SIZEOF_PTR+3))-1))
-		    : lg_floor((size<<1)-1);
+		size_t x = lg_floor((size<<1)-1);
 		size_t lg_delta = (x < LG_SIZE_CLASS_GROUP + LG_QUANTUM + 1)
 		    ?  LG_QUANTUM : x - LG_SIZE_CLASS_GROUP - 1;
 		size_t delta = ZU(1) << lg_delta;
diff --git a/include/jemalloc/internal/private_symbols.txt b/include/jemalloc/internal/private_symbols.txt
index f2b6a55..a9d6973 100644
--- a/include/jemalloc/internal/private_symbols.txt
+++ b/include/jemalloc/internal/private_symbols.txt
@@ -401,6 +401,7 @@ pages_map
 pages_purge
 pages_trim
 pages_unmap
+pind2sz
 pow2_ceil_u32
 pow2_ceil_u64
 pow2_ceil_zu
@@ -454,6 +455,8 @@ prof_thread_active_init_set
 prof_thread_active_set
 prof_thread_name_get
 prof_thread_name_set
+psz2ind
+psz2u
 purge_mode_names
 quarantine
 quarantine_alloc_hook
diff --git a/include/jemalloc/internal/size_classes.sh b/include/jemalloc/internal/size_classes.sh
index 2b0ca29..f6fbce4 100755
--- a/include/jemalloc/internal/size_classes.sh
+++ b/include/jemalloc/internal/size_classes.sh
@@ -48,6 +48,21 @@ size_class() {
   lg_p=$5
   lg_kmax=$6
 
+  if [ ${lg_delta} -ge ${lg_p} ] ; then
+    psz="yes"
+  else
+    pow2 ${lg_p}; p=${pow2_result}
+    pow2 ${lg_grp}; grp=${pow2_result}
+    pow2 ${lg_delta}; delta=${pow2_result}
+    sz=$((${grp} + ${delta} * ${ndelta}))
+    npgs=$((${sz} / ${p}))
+    if [ ${sz} -eq $((${npgs} * ${p})) ] ; then
+      psz="yes"
+    else
+      psz="no"
+    fi
+  fi
+
   lg ${ndelta}; lg_ndelta=${lg_result}; pow2 ${lg_ndelta}
   if [ ${pow2_result} -lt ${ndelta} ] ; then
     rem="yes"
@@ -74,14 +89,15 @@ size_class() {
   else
     lg_delta_lookup="no"
   fi
-  printf '    SC(%3d, %6d, %8d, %6d, %3s, %2s) \\\n' ${index} ${lg_grp} ${lg_delta} ${ndelta} ${bin} ${lg_delta_lookup}
+  printf '    SC(%3d, %6d, %8d, %6d, %3s, %3s, %2s) \\\n' ${index} ${lg_grp} ${lg_delta} ${ndelta} ${psz} ${bin} ${lg_delta_lookup}
   # Defined upon return:
-  # - lg_delta_lookup (${lg_delta} or "no")
+  # - psz ("yes" or "no")
   # - bin ("yes" or "no")
+  # - lg_delta_lookup (${lg_delta} or "no")
 }
 
 sep_line() {
-  echo "                                               \\"
+  echo "                                                         \\"
 }
 
 size_classes() {
@@ -95,12 +111,13 @@ size_classes() {
   pow2 ${lg_g}; g=${pow2_result}
 
   echo "#define	SIZE_CLASSES \\"
-  echo "  /* index, lg_grp, lg_delta, ndelta, bin, lg_delta_lookup */ \\"
+  echo "  /* index, lg_grp, lg_delta, ndelta, psz, bin, lg_delta_lookup */ \\"
 
   ntbins=0
   nlbins=0
   lg_tiny_maxclass='"NA"'
   nbins=0
+  npsizes=0
 
   # Tiny size classes.
   ndelta=0
@@ -112,6 +129,9 @@ size_classes() {
     if [ ${lg_delta_lookup} != "no" ] ; then
       nlbins=$((${index} + 1))
     fi
+    if [ ${psz} = "yes" ] ; then
+      npsizes=$((${npsizes} + 1))
+    fi
     if [ ${bin} != "no" ] ; then
       nbins=$((${index} + 1))
     fi
@@ -133,11 +153,17 @@ size_classes() {
     index=$((${index} + 1))
     lg_grp=$((${lg_grp} + 1))
     lg_delta=$((${lg_delta} + 1))
+    if [ ${psz} = "yes" ] ; then
+      npsizes=$((${npsizes} + 1))
+    fi
   fi
   while [ ${ndelta} -lt ${g} ] ; do
     size_class ${index} ${lg_grp} ${lg_delta} ${ndelta} ${lg_p} ${lg_kmax}
     index=$((${index} + 1))
     ndelta=$((${ndelta} + 1))
+    if [ ${psz} = "yes" ] ; then
+      npsizes=$((${npsizes} + 1))
+    fi
   done
 
   # All remaining groups.
@@ -157,6 +183,9 @@ size_classes() {
         # Final written value is correct:
         lookup_maxclass="((((size_t)1) << ${lg_grp}) + (((size_t)${ndelta}) << ${lg_delta}))"
       fi
+      if [ ${psz} = "yes" ] ; then
+        npsizes=$((${npsizes} + 1))
+      fi
       if [ ${bin} != "no" ] ; then
         nbins=$((${index} + 1))
         # Final written value is correct:
@@ -183,6 +212,7 @@ size_classes() {
   # - nlbins
   # - nbins
   # - nsizes
+  # - npsizes
   # - lg_tiny_maxclass
   # - lookup_maxclass
   # - small_maxclass
@@ -200,13 +230,13 @@ cat <<EOF
  * be defined prior to inclusion, and it in turn defines:
  *
  *   LG_SIZE_CLASS_GROUP: Lg of size class count for each size doubling.
- *   SIZE_CLASSES: Complete table of
- *                 SC(index, lg_grp, lg_delta, ndelta, bin, lg_delta_lookup)
- *                 tuples.
+ *   SIZE_CLASSES: Complete table of SC(index, lg_grp, lg_delta, ndelta, psz,
+ *                 bin, lg_delta_lookup) tuples.
  *     index: Size class index.
  *     lg_grp: Lg group base size (no deltas added).
  *     lg_delta: Lg delta to previous size class.
  *     ndelta: Delta multiplier.  size == 1<<lg_grp + ndelta<<lg_delta
+ *     psz: 'yes' if a multiple of the page size, 'no' otherwise.
  *     bin: 'yes' if a small bin size class, 'no' otherwise.
  *     lg_delta_lookup: Same as lg_delta if a lookup table size class, 'no'
  *                      otherwise.
@@ -214,6 +244,7 @@ cat <<EOF
  *   NLBINS: Number of bins supported by the lookup table.
  *   NBINS: Number of small size class bins.
  *   NSIZES: Number of size classes.
+ *   NPSIZES: Number of size classes that are a multiple of (1U << LG_PAGE).
  *   LG_TINY_MAXCLASS: Lg of maximum tiny size class.
  *   LOOKUP_MAXCLASS: Maximum size class included in lookup table.
  *   SMALL_MAXCLASS: Maximum small size class.
@@ -238,6 +269,7 @@ for lg_z in ${lg_zarr} ; do
         echo "#define	NLBINS			${nlbins}"
         echo "#define	NBINS			${nbins}"
         echo "#define	NSIZES			${nsizes}"
+        echo "#define	NPSIZES			${npsizes}"
         echo "#define	LG_TINY_MAXCLASS	${lg_tiny_maxclass}"
         echo "#define	LOOKUP_MAXCLASS		${lookup_maxclass}"
         echo "#define	SMALL_MAXCLASS		${small_maxclass}"