| Message ID | 4c366314-a9b8-e1ff-9d6c-dc4f11eca41c@e124511.cambridge.arm.com |
|---|---|
| State | New |
| Headers | show |
| Series | aarch64: FMV feature list fixes | expand |
Andrew Carlotti <andrew.carlotti@arm.com> writes: > There was an assumption in some places that the aarch64_fmv_feature_data > array contained FEAT_MAX elements. While this assumption held up till > now, it is safer and more flexible to use the array size directly. > > gcc/ChangeLog: > > * config/aarch64/aarch64.cc (compare_feature_masks): > Use ARRAY_SIZE to determine iteration bounds. > (aarch64_mangle_decl_assembler_name): Ditto. > > > diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc > index 1ea84c8bd7386e399f6ffa3a5e36408cf8831fc6..5de842fcc212c78beba1fa99639e79562d718579 100644 > --- a/gcc/config/aarch64/aarch64.cc > +++ b/gcc/config/aarch64/aarch64.cc > @@ -19899,7 +19899,8 @@ compare_feature_masks (aarch64_fmv_feature_mask mask1, > auto diff_mask = mask1 ^ mask2; > if (diff_mask == 0ULL) > return 0; > - for (int i = FEAT_MAX - 1; i > 0; i--) > + static const int num_features = ARRAY_SIZE (aarch64_fmv_feature_data); There doesn't seem any need for this to be static (or const). Same for the second hunk. > + for (int i = num_features - 1; i > 0; i--) Pre-existing, but is > 0 rather than >= 0 deliberate? Shouldn't we look at index 0 as well? LGTM otherwise. Thanks, Richard > { > auto bit_mask = aarch64_fmv_feature_data[i].feature_mask; > if (diff_mask & bit_mask) > @@ -19982,7 +19983,8 @@ aarch64_mangle_decl_assembler_name (tree decl, tree id) > > name += "._"; > > - for (int i = 0; i < FEAT_MAX; i++) > + static const int num_features = ARRAY_SIZE (aarch64_fmv_feature_data); > + for (int i = 0; i < num_features; i++) > { > if (feature_mask & aarch64_fmv_feature_data[i].feature_mask) > {
On Tue, Apr 09, 2024 at 04:33:10PM +0100, Richard Sandiford wrote: > Andrew Carlotti <andrew.carlotti@arm.com> writes: > > There was an assumption in some places that the aarch64_fmv_feature_data > > array contained FEAT_MAX elements. While this assumption held up till > > now, it is safer and more flexible to use the array size directly. > > > > gcc/ChangeLog: > > > > * config/aarch64/aarch64.cc (compare_feature_masks): > > Use ARRAY_SIZE to determine iteration bounds. > > (aarch64_mangle_decl_assembler_name): Ditto. > > > > > > diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc > > index 1ea84c8bd7386e399f6ffa3a5e36408cf8831fc6..5de842fcc212c78beba1fa99639e79562d718579 100644 > > --- a/gcc/config/aarch64/aarch64.cc > > +++ b/gcc/config/aarch64/aarch64.cc > > @@ -19899,7 +19899,8 @@ compare_feature_masks (aarch64_fmv_feature_mask mask1, > > auto diff_mask = mask1 ^ mask2; > > if (diff_mask == 0ULL) > > return 0; > > - for (int i = FEAT_MAX - 1; i > 0; i--) > > + static const int num_features = ARRAY_SIZE (aarch64_fmv_feature_data); > > There doesn't seem any need for this to be static (or const). Same for > the second hunk. Agreed - I'll fix that, and the other instance I added in a previous patch. I originally copied this pattern from my driver-aarch64.c:252, which was added by Kyrill back in 2015. > > + for (int i = num_features - 1; i > 0; i--) > > Pre-existing, but is > 0 rather than >= 0 deliberate? Shouldn't we look > at index 0 as well? That was probably left over from when "default" was handled as part of the list. I think a different instance of this mistake was mentioned in a previous review. I'll fix this mistake and add a test. > LGTM otherwise. > > Thanks, > Richard > > > { > > auto bit_mask = aarch64_fmv_feature_data[i].feature_mask; > > if (diff_mask & bit_mask) > > @@ -19982,7 +19983,8 @@ aarch64_mangle_decl_assembler_name (tree decl, tree id) > > > > name += "._"; > > > > - for (int i = 0; i < FEAT_MAX; i++) > > + static const int num_features = ARRAY_SIZE (aarch64_fmv_feature_data); > > + for (int i = 0; i < num_features; i++) > > { > > if (feature_mask & aarch64_fmv_feature_data[i].feature_mask) > > {
diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc index 1ea84c8bd7386e399f6ffa3a5e36408cf8831fc6..5de842fcc212c78beba1fa99639e79562d718579 100644 --- a/gcc/config/aarch64/aarch64.cc +++ b/gcc/config/aarch64/aarch64.cc @@ -19899,7 +19899,8 @@ compare_feature_masks (aarch64_fmv_feature_mask mask1, auto diff_mask = mask1 ^ mask2; if (diff_mask == 0ULL) return 0; - for (int i = FEAT_MAX - 1; i > 0; i--) + static const int num_features = ARRAY_SIZE (aarch64_fmv_feature_data); + for (int i = num_features - 1; i > 0; i--) { auto bit_mask = aarch64_fmv_feature_data[i].feature_mask; if (diff_mask & bit_mask) @@ -19982,7 +19983,8 @@ aarch64_mangle_decl_assembler_name (tree decl, tree id) name += "._"; - for (int i = 0; i < FEAT_MAX; i++) + static const int num_features = ARRAY_SIZE (aarch64_fmv_feature_data); + for (int i = 0; i < num_features; i++) { if (feature_mask & aarch64_fmv_feature_data[i].feature_mask) {