From b5515692062b50e592c3c6e625170406b4ce5c45 Mon Sep 17 00:00:00 2001
From: Christopher Haster <geky@geky.net>
Date: Wed, 5 Feb 2025 01:08:19 -0600
Subject: [PATCH] Adopted LFS_FORCEINLINE

May revisit this in the future, but this is the best solution I can
think of right now, that doesn't run into duplicate macro-argument
side-effect issues...

Statement expressions would be another solution, but that's even less
portable!

At the moment this is only used for functions that implement
LFSR_DATA_* and LFSR_RAT_* macros. These _need_ to be inlined to avoid a
large code-size explosion, and GCC seems to have issues with this.

For most of the other inlinable functions, relying on C99's inline +
compiler heuristics seems to be fine.

Code changes:

  before:          36304           2576          640
  no-forceinline:  36460 (+0.4%)   2664 (+3.4%)  640 (+0.0%)
  yes-forceinline: 36300 (-0.0%)   2576 (+0.0%)  640 (+0.0%)
---
 lfs.c      | 20 +++++++++++---------
 lfs_util.h | 10 ++++++++++
 2 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/lfs.c b/lfs.c
index 84f48da2..8f72164f 100644
--- a/lfs.c
+++ b/lfs.c
@@ -1663,8 +1663,10 @@ static inline lfs_size_t lfsr_data_size(lfsr_data_t data) {
 }
 
 // data slicing
-// TODO what to do about this inlining situation?
-__attribute__((always_inline))
+#define LFSR_DATA_SLICE(_data, _off, _size) \
+    ((struct {lfsr_data_t d;}){lfsr_data_fromslice(_data, _off, _size)}.d)
+
+LFS_FORCEINLINE
 static inline lfsr_data_t lfsr_data_fromslice(lfsr_data_t data,
         lfs_ssize_t off, lfs_ssize_t size) {
     // limit our off/size to data range, note the use of unsigned casts
@@ -1690,17 +1692,19 @@ static inline lfsr_data_t lfsr_data_fromslice(lfsr_data_t data,
     return data;
 }
 
-#define LFSR_DATA_SLICE(_data, _off, _size) \
-    ((struct {lfsr_data_t d;}){lfsr_data_fromslice(_data, _off, _size)}.d)
+#define LFSR_DATA_TRUNCATE(_data, _size) \
+    ((struct {lfsr_data_t d;}){lfsr_data_fromtruncate(_data, _size)}.d)
 
+LFS_FORCEINLINE
 static inline lfsr_data_t lfsr_data_fromtruncate(lfsr_data_t data,
         lfs_size_t size) {
     return LFSR_DATA_SLICE(data, -1, size);
 }
 
-#define LFSR_DATA_TRUNCATE(_data, _size) \
-    ((struct {lfsr_data_t d;}){lfsr_data_fromtruncate(_data, _size)}.d)
+#define LFSR_DATA_FRUNCATE(_data, _size) \
+    ((struct {lfsr_data_t d;}){lfsr_data_fromfruncate(_data, _size)}.d)
 
+LFS_FORCEINLINE
 static inline lfsr_data_t lfsr_data_fromfruncate(lfsr_data_t data,
         lfs_size_t size) {
     return LFSR_DATA_SLICE(data,
@@ -1710,9 +1714,6 @@ static inline lfsr_data_t lfsr_data_fromfruncate(lfsr_data_t data,
             -1);
 }
 
-#define LFSR_DATA_FRUNCATE(_data, _size) \
-    ((struct {lfsr_data_t d;}){lfsr_data_fromfruncate(_data, _size)}.d)
-
 
 // macros for le32/leb128/lleb128 encoding, these are useful for
 // building rats
@@ -2023,6 +2024,7 @@ typedef struct lfsr_rat {
 #define LFSR_RAT(_tag, _weight, _data) \
     ((struct {lfsr_rat_t a;}){lfsr_rat(_tag, _weight, _data)}.a)
 
+LFS_FORCEINLINE
 static inline lfsr_rat_t lfsr_rat(
         lfsr_tag_t tag, lfsr_srid_t weight, lfsr_data_t data) {
     // only simple data works here
diff --git a/lfs_util.h b/lfs_util.h
index 79d9ebc8..b46eaff3 100644
--- a/lfs_util.h
+++ b/lfs_util.h
@@ -229,6 +229,16 @@ extern "C"
 #endif
 
 
+// Some function attributes, no way around these
+
+// Force a function to be inlined
+#if !defined(LFS_NO_BUILTINS) && defined(__GNUC__)
+#define LFS_FORCEINLINE __attribute__((always_inline))
+#else
+#define LFS_FORCEINLINE
+#endif
+
+
 // Builtin functions, these may be replaced by more efficient
 // toolchain-specific implementations. LFS_NO_BUILTINS falls back to a more
 // expensive basic C implementation for debugging purposes