diff options
Diffstat (limited to 'meta-oe/recipes-benchmark/lmbench/lmbench/0001-avoid-gcc-optimize-away-the-loops.patch')
-rw-r--r-- | meta-oe/recipes-benchmark/lmbench/lmbench/0001-avoid-gcc-optimize-away-the-loops.patch | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/meta-oe/recipes-benchmark/lmbench/lmbench/0001-avoid-gcc-optimize-away-the-loops.patch b/meta-oe/recipes-benchmark/lmbench/lmbench/0001-avoid-gcc-optimize-away-the-loops.patch new file mode 100644 index 0000000000..2d8a2468a9 --- /dev/null +++ b/meta-oe/recipes-benchmark/lmbench/lmbench/0001-avoid-gcc-optimize-away-the-loops.patch @@ -0,0 +1,79 @@ +[PATCH] avoid gcc optimize-away the loops + +Upstream-Status: pending + +Change expression used in do_integer_mul and do_uint64_mul +benchmarks so GCC doesn't optimize-away the loops, other +things are same: +- TEN(r *= s;); r -= t; ++ i = 0; ++ while ( i++ < 10) ++ r *= s; ++ r -= t; + +and TEN is macro: + #define TEN(a) a a a a a a a a a a + +Signed-off-by: Roy Li <rongqing.li@windriver.com> +--- + src/lat_ops.c | 30 +++++++++++++++++++++++++----- + 1 file changed, 25 insertions(+), 5 deletions(-) + +diff --git a/src/lat_ops.c b/src/lat_ops.c +index d343ff3..457072b 100644 +--- a/src/lat_ops.c ++++ b/src/lat_ops.c +@@ -126,11 +126,23 @@ do_integer_mul(iter_t iterations, void* cookie) + struct _state *pState = (struct _state*)cookie; + register int r = pState->N + 37431; + register int s = pState->N + 4; +- register int t = r * s * s * s * s * s * s * s * s * s * s - r; ++ register int t = r; ++ int i = 0; ++ ++ while ( i++ < 10) ++ t *= s; ++ t -= r; + + while (iterations-- > 0) { +- TEN(r *= s;); r -= t; +- TEN(r *= s;); r -= t; ++ i = 0; ++ while ( i++ < 10) ++ r *= s; ++ r -= t; ++ ++ i = 0; ++ while ( i++ < 10) ++ r *= s; ++ r -= t; + } + use_int(r); + } +@@ -207,13 +219,21 @@ do_int64_mul(iter_t iterations, void* cookie) + register int64 r = (int64)pState->N + 37420; + register int64 s = (int64)pState->N + 4; + register int64 t; ++ int i = 0; + + r += (int64)(pState->N + 6)<<32; + t = r * s * s * s * s * s * s * s * s * s * s - r; + + while (iterations-- > 0) { +- TEN(r *= s;); r -= t; +- TEN(r *= s;); r -= t; ++ i = 0; ++ while ( i++ < 10) ++ r *= s; ++ r -= t; ++ ++ i = 0; ++ while ( i++ < 10) ++ r *= s; ++ r -= t; + } + use_int((int)r); + } +-- +2.8.1 + |