[glibc] benchtests: Add additional cases to bench-memcpy.c and bench-memmove.c

[glibc] benchtests: Add additional cases to bench-memcpy.c and bench-memmove.c

[Noah Goldstein]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=5e6cce9b34e1609dc5183312a9efaf0d420a547a

commit 5e6cce9b34e1609dc5183312a9efaf0d420a547a
Author: Noah Goldstein <goldstein.w.n@gmail.com>
Date:   Mon Nov 1 00:49:49 2021 -0500

    benchtests: Add additional cases to bench-memcpy.c and bench-memmove.c
    
    This commit adds more benchmarks for the common memcpy/memmove
    benchmarks. The most signifcant cases are the half page offsets. The
    current versions leaves dst and src near page aligned which leads to
    false 4k aliasing on x86_64. This can add noise due to false
    dependencies from one run to the next. As well, this seems like more
    of an edge case that common case so it shouldn't be the only thing
    
    Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
    Reviewed-by: H.J. Lu <hjl.tools@gmail.com>

Diff:
---
 benchtests/bench-memcpy.c  | 49 ++++++++++++++++++++++++++++++++++++++++------
 benchtests/bench-memmove.c | 26 +++++++++++++++++++++---
 2 files changed, 66 insertions(+), 9 deletions(-)

diff --git a/benchtests/bench-memcpy.c b/benchtests/bench-memcpy.c
index d9236a2282..744bea26d3 100644
--- a/benchtests/bench-memcpy.c
+++ b/benchtests/bench-memcpy.c
@@ -40,7 +40,10 @@ do_one_test (json_ctx_t *json_ctx, impl_t *impl, char *dst, const char *src,
 {
   size_t i, iters = INNER_LOOP_ITERS;
   timing_t start, stop, cur;
-
+  for (i = 0; i < iters / 64; ++i)
+    {
+      CALL (impl, dst, src, len);
+    }
   TIMING_NOW (start);
   for (i = 0; i < iters; ++i)
     {
@@ -60,11 +63,11 @@ do_test (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len,
   size_t i, j;
   char *s1, *s2;
   size_t repeats;
-  align1 &= 63;
+  align1 &= (getpagesize () - 1);
   if (align1 + len >= page_size)
     return;
 
-  align2 &= 63;
+  align2 &= (getpagesize () - 1);
   if (align2 + len >= page_size)
     return;
 
@@ -99,7 +102,7 @@ test_main (void)
 {
   json_ctx_t json_ctx;
   size_t i;
-
+  size_t half_page = getpagesize () / 2;
   test_init ();
 
   json_init (&json_ctx, 0, stdout);
@@ -121,8 +124,15 @@ test_main (void)
     {
       do_test (&json_ctx, 0, 0, 1 << i, 1);
       do_test (&json_ctx, i, 0, 1 << i, 1);
+      do_test (&json_ctx, i + 32, 0, 1 << i, 1);
       do_test (&json_ctx, 0, i, 1 << i, 1);
+      do_test (&json_ctx, 0, i + 32, 1 << i, 1);
       do_test (&json_ctx, i, i, 1 << i, 1);
+      do_test (&json_ctx, i + 32, i + 32, 1 << i, 1);
+      do_test (&json_ctx, half_page, 0, 1 << i, 1);
+      do_test (&json_ctx, half_page + i, 0, 1 << i, 1);
+      do_test (&json_ctx, half_page, i, 1 << i, 1);
+      do_test (&json_ctx, half_page + i, i, 1 << i, 1);
     }
 
   for (i = 0; i < 32; ++i)
@@ -131,16 +141,26 @@ test_main (void)
       do_test (&json_ctx, i, 0, i, 0);
       do_test (&json_ctx, 0, i, i, 0);
       do_test (&json_ctx, i, i, i, 0);
+      do_test (&json_ctx, half_page, 0, i, 0);
+      do_test (&json_ctx, half_page + i, 0, i, 0);
+      do_test (&json_ctx, half_page, i, i, 0);
+      do_test (&json_ctx, half_page + i, i, i, 0);
+      do_test (&json_ctx, getpagesize () - 1, 0, i, 0);
+      do_test (&json_ctx, 0, getpagesize () - 1, i, 0);
     }
 
   for (i = 3; i < 32; ++i)
     {
       if ((i & (i - 1)) == 0)
-	continue;
+        continue;
       do_test (&json_ctx, 0, 0, 16 * i, 1);
       do_test (&json_ctx, i, 0, 16 * i, 1);
       do_test (&json_ctx, 0, i, 16 * i, 1);
       do_test (&json_ctx, i, i, 16 * i, 1);
+      do_test (&json_ctx, half_page, 0, 16 * i, 1);
+      do_test (&json_ctx, half_page + i, 0, 16 * i, 1);
+      do_test (&json_ctx, half_page, i, 16 * i, 1);
+      do_test (&json_ctx, half_page + i, i, 16 * i, 1);
     }
 
   for (i = 32; i < 64; ++i)
@@ -149,16 +169,33 @@ test_main (void)
       do_test (&json_ctx, i, 0, 32 * i, 1);
       do_test (&json_ctx, 0, i, 32 * i, 1);
       do_test (&json_ctx, i, i, 32 * i, 1);
+      do_test (&json_ctx, half_page, 0, 32 * i, 1);
+      do_test (&json_ctx, half_page + i, 0, 32 * i, 1);
+      do_test (&json_ctx, half_page, i, 32 * i, 1);
+      do_test (&json_ctx, half_page + i, i, 32 * i, 1);
     }
 
   do_test (&json_ctx, 0, 0, getpagesize (), 1);
 
-  for (i = 0; i <= 32; ++i)
+  for (i = 0; i <= 48; ++i)
     {
       do_test (&json_ctx, 0, 0, 2048 + 64 * i, 1);
       do_test (&json_ctx, i, 0, 2048 + 64 * i, 1);
+      do_test (&json_ctx, i + 32, 0, 2048 + 64 * i, 1);
       do_test (&json_ctx, 0, i, 2048 + 64 * i, 1);
+      do_test (&json_ctx, 0, i + 32, 2048 + 64 * i, 1);
       do_test (&json_ctx, i, i, 2048 + 64 * i, 1);
+      do_test (&json_ctx, i + 32, i + 32, 2048 + 64 * i, 1);
+      do_test (&json_ctx, half_page, 0, 2048 + 64 * i, 1);
+      do_test (&json_ctx, half_page + i, 0, 2048 + 64 * i, 1);
+      do_test (&json_ctx, half_page, i, 2048 + 64 * i, 1);
+      do_test (&json_ctx, half_page + i, i, 2048 + 64 * i, 1);
+      do_test (&json_ctx, i, 1, 2048 + 64 * i, 1);
+      do_test (&json_ctx, 1, i, 2048 + 64 * i, 1);
+      do_test (&json_ctx, i + 32, 1, 2048 + 64 * i, 1);
+      do_test (&json_ctx, 1, i + 32, 2048 + 64 * i, 1);
+      do_test (&json_ctx, half_page + i, 1, 2048 + 64 * i, 1);
+      do_test (&json_ctx, half_page + 1, i, 2048 + 64 * i, 1);
     }
 
   json_array_end (&json_ctx);
diff --git a/benchtests/bench-memmove.c b/benchtests/bench-memmove.c
index 6becbf4782..855f4d0649 100644
--- a/benchtests/bench-memmove.c
+++ b/benchtests/bench-memmove.c
@@ -34,7 +34,10 @@ do_one_test (json_ctx_t *json_ctx, impl_t *impl, char *dst, char *src,
 {
   size_t i, iters = INNER_LOOP_ITERS;
   timing_t start, stop, cur;
-
+  for (i = 0; i < iters / 64; ++i)
+    {
+      CALL (impl, dst, src, len);
+    }
   TIMING_NOW (start);
   for (i = 0; i < iters; ++i)
     {
@@ -53,11 +56,11 @@ do_test (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len)
   size_t i, j;
   char *s1, *s2;
 
-  align1 &= 63;
+  align1 &= (getpagesize () - 1);
   if (align1 + len >= page_size)
     return;
 
-  align2 &= 63;
+  align2 &= (getpagesize () - 1);
   if (align2 + len >= page_size)
     return;
 
@@ -85,6 +88,7 @@ test_main (void)
 {
   json_ctx_t json_ctx;
   size_t i;
+  size_t half_page = getpagesize () / 2;
 
   test_init ();
 
@@ -138,6 +142,22 @@ test_main (void)
       do_test (&json_ctx, i, i, 32 * i);
     }
 
+  for (i = 0; i <= 48; ++i)
+    {
+      do_test (&json_ctx, 0, 0, 2048 + 64 * i);
+      do_test (&json_ctx, i, 0, 2048 + 64 * i);
+      do_test (&json_ctx, 0, i, 2048 + 64 * i);
+      do_test (&json_ctx, i, i, 2048 + 64 * i);
+      do_test (&json_ctx, half_page, 0, 2048 + 64 * i);
+      do_test (&json_ctx, 0, half_page, 2048 + 64 * i);
+      do_test (&json_ctx, half_page + i, 0, 2048 + 64 * i);
+      do_test (&json_ctx, i, half_page, 2048 + 64 * i);
+      do_test (&json_ctx, half_page, i, 2048 + 64 * i);
+      do_test (&json_ctx, 0, half_page + i, 2048 + 64 * i);
+      do_test (&json_ctx, half_page + i, i, 2048 + 64 * i);
+      do_test (&json_ctx, i, half_page + i, 2048 + 64 * i);
+    }
+
   json_array_end (&json_ctx);
   json_attr_object_end (&json_ctx);
   json_attr_object_end (&json_ctx);