Use __builtin_constant_p() to select the best byteswapping method: constant or target optimized. Same macro can then be used for constant values and inits as well as non-constant.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@29171 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 18 insertions, 6 deletions

diff --git a/firmware/target/arm/system-arm.h b/firmware/target/arm/system-arm.h
index 0608f50a02..e77b786866 100644
--- a/firmware/target/arm/system-arm.h
+++ b/firmware/target/arm/system-arm.h
@@ -90,7 +90,7 @@ static inline void restore_interrupt(int cpsr)
 /* ARM_ARCH version section for architecture*/
 
 #if ARM_ARCH >= 6
-static inline uint16_t swap16(uint16_t value)
+static inline uint16_t swap16_hw(uint16_t value)
     /*
       result[15..8] = value[ 7..0];
       result[ 7..0] = value[15..8];
@@ -102,7 +102,7 @@ static inline uint16_t swap16(uint16_t value)
     return retval;
 }
 
-static inline uint32_t swap32(uint32_t value)
+static inline uint32_t swap32_hw(uint32_t value)
     /*
       result[31..24] = value[ 7.. 0];
       result[23..16] = value[15.. 8];
@@ -116,7 +116,7 @@ static inline uint32_t swap32(uint32_t value)
     return retval;
 }
 
-static inline uint32_t swap_odd_even32(uint32_t value)
+static inline uint32_t swap_odd_even32_hw(uint32_t value)
 {
     /*
       result[31..24],[15.. 8] = value[23..16],[ 7.. 0]
@@ -190,7 +190,7 @@ static inline int disable_interrupt_save(int mask)
 
 #else /* ARM_ARCH < 6 */
 
-static inline uint16_t swap16(uint16_t value)
+static inline uint16_t swap16_hw(uint16_t value)
     /*
       result[15..8] = value[ 7..0];
       result[ 7..0] = value[15..8];
@@ -199,7 +199,7 @@ static inline uint16_t swap16(uint16_t value)
     return (value >> 8) | (value << 8);
 }
 
-static inline uint32_t swap32(uint32_t value)
+static inline uint32_t swap32_hw(uint32_t value)
     /*
       result[31..24] = value[ 7.. 0];
       result[23..16] = value[15.. 8];
@@ -218,7 +218,7 @@ static inline uint32_t swap32(uint32_t value)
     return value;
 }
 
-static inline uint32_t swap_odd_even32(uint32_t value)
+static inline uint32_t swap_odd_even32_hw(uint32_t value)
 {
     /*
       result[31..24],[15.. 8] = value[23..16],[ 7.. 0]
@@ -272,4 +272,16 @@ static inline int disable_interrupt_save(int mask)
 
 #endif /* ARM_ARCH */
 
+static inline uint32_t swaw32_hw(uint32_t value)
+{
+    /*
+      result[31..16] = value[15.. 0];
+      result[15.. 0] = value[31..16];
+    */
+    uint32_t retval;
+    asm volatile ("mov %0, %1, ror #16" :
+                  "=r"(retval) : "r"(value));
+    return retval;
+}
+
 #endif /* SYSTEM_ARM_H */