# HG changeset patch
# User nickg
# Date 1233747227 0
# Node ID 403e17f06bec760ea65874f82a1730ed9f118a62
# Parent  b8eabd9f6ab3cf2459f33cc2aa1d61b3b460482c
Add support for overriding bit index macros.

diff --git a/packages/hal/mips/arch/current/ChangeLog b/packages/hal/mips/arch/current/ChangeLog
--- a/packages/hal/mips/arch/current/ChangeLog
+++ b/packages/hal/mips/arch/current/ChangeLog
@@ -1,3 +1,8 @@
+2009-02-04  Nick Garnett  <nickg@ecoscentric.com>
+
+	* include/hal_arch.h: Ifdef bit index macros to allow them to be
+	overridden by variant or platform HAL.
+
 2004-05-27  Gary Thomas  <gary@mlbassoc.com>
 
 	* src/redboot_linux_exec.c (do_exec): Be sensitive to value in
diff --git a/packages/hal/mips/arch/current/include/hal_arch.h b/packages/hal/mips/arch/current/include/hal_arch.h
--- a/packages/hal/mips/arch/current/include/hal_arch.h
+++ b/packages/hal/mips/arch/current/include/hal_arch.h
@@ -125,6 +125,8 @@ externC void cyg_hal_deliver_exception( 
 //--------------------------------------------------------------------------
 // Bit manipulation macros
 
+#ifndef CYGHWR_HAL_BIT_INDEXES_DEFINED
+
 externC cyg_uint32 hal_lsbit_index(cyg_uint32 mask);
 externC cyg_uint32 hal_msbit_index(cyg_uint32 mask);
 
@@ -132,6 +134,8 @@ externC cyg_uint32 hal_msbit_index(cyg_u
 
 #define HAL_MSBIT_INDEX(index, mask) index = hal_msbit_index(mask);
 
+#endif
+
 //--------------------------------------------------------------------------
 // Context Initialization
 
diff --git a/packages/hal/mips/mips32/current/ChangeLog b/packages/hal/mips/mips32/current/ChangeLog
--- a/packages/hal/mips/mips32/current/ChangeLog
+++ b/packages/hal/mips/mips32/current/ChangeLog
@@ -1,3 +1,8 @@
+2009-02-04  Nick Garnett  <nickg@ecoscentric.com>
+
+	* include/var_arch.h (HAL_LSBIT_INDEX, HAL_MSBIT_INDEX): Provide
+	overrides for these macros that use the clz instruction.
+
 2009-01-31  Bart Veer <bartv@ecoscentric.com>
 
 	* cdl/hal_mips_mips32.cdl: update compiler flags for gcc 4.x
diff --git a/packages/hal/mips/mips32/current/include/var_arch.h b/packages/hal/mips/mips32/current/include/var_arch.h
--- a/packages/hal/mips/mips32/current/include/var_arch.h
+++ b/packages/hal/mips/mips32/current/include/var_arch.h
@@ -85,6 +85,43 @@
         HAL_SET_CP0_REGISTER_32( _regval_, _cp0_regno_, _cp0_regsel_ )
 
 //--------------------------------------------------------------------------
+// Bit manipulation macros
+
+#ifndef CYGHWR_HAL_BIT_INDEXES_DEFINED
+
+//--------------------------------------------------------
+// Determine the index of the ls bit of the supplied mask.
+
+#define HAL_LSBIT_INDEX(_index_, _mask_)                                \
+    CYG_MACRO_START                                                     \
+    unsigned _reg_;                                                     \
+                                                                        \
+    _reg_ = (_mask_);                                                   \
+    _reg_ &= -_reg_;                                                    \
+    asm volatile ("clz    %0, %1\n"                                     \
+               : "=r" (_reg_)                                           \
+               : "r" (_reg_) );                                         \
+    (_index_) = 31 - _reg_;                                             \
+    CYG_MACRO_END
+
+//--------------------------------------------------------
+// Determine the index of the ms bit of the supplied mask.
+
+#define HAL_MSBIT_INDEX(_index_, _mask_)                                \
+    CYG_MACRO_START                                                     \
+    unsigned _reg_;                                                     \
+                                                                        \
+    _reg_ = (_mask_);                                                   \
+    asm volatile ("clz    %0, %1\n"                                     \
+             : "=r" (_reg_)                                             \
+             : "r" (_reg_) );                                           \
+    (_index_) = 31 - _reg_;                                             \
+    CYG_MACRO_END
+
+#define CYGHWR_HAL_BIT_INDEXES_DEFINED
+#endif
+
+//--------------------------------------------------------------------------
 
 #ifdef CYGARC_HAL_COMMON_EXPORT_CPU_MACROS
 /* System Control Coprocessor (CP0) exception processing registers */