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Diffstat (limited to 'src/third_party/js-1.7/lock_SunOS.s')
| -rw-r--r-- | src/third_party/js-1.7/lock_SunOS.s | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/src/third_party/js-1.7/lock_SunOS.s b/src/third_party/js-1.7/lock_SunOS.s new file mode 100644 index 00000000000..7a842d186e0 --- /dev/null +++ b/src/third_party/js-1.7/lock_SunOS.s @@ -0,0 +1,114 @@ +! +! The contents of this file are subject to the Netscape Public +! License Version 1.1 (the "License"); you may not use this file +! except in compliance with the License. You may obtain a copy of +! the License at http://www.mozilla.org/NPL/ +! +! Software distributed under the License is distributed on an "AS +! IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or +! implied. See the License for the specific language governing +! rights and limitations under the License. +! +! The Original Code is Mozilla Communicator client code, released +! March 31, 1998. +! +! The Initial Developer of the Original Code is Netscape +! Communications Corporation. Portions created by Netscape are +! Copyright (C) 1998-1999 Netscape Communications Corporation. All +! Rights Reserved. +! +! Contributor(s): +! +! Alternatively, the contents of this file may be used under the +! terms of the GNU Public License (the "GPL"), in which case the +! provisions of the GPL are applicable instead of those above. +! If you wish to allow use of your version of this file only +! under the terms of the GPL and not to allow others to use your +! version of this file under the NPL, indicate your decision by +! deleting the provisions above and replace them with the notice +! and other provisions required by the GPL. If you do not delete +! the provisions above, a recipient may use your version of this +! file under either the NPL or the GPL. +! + +! +! atomic compare-and-swap routines for V8 sparc +! and for V8+ (ultrasparc) +! +! +! standard asm linkage macros; this module must be compiled +! with the -P option (use C preprocessor) + +#include <sys/asm_linkage.h> + +! ====================================================================== +! +! Perform the sequence *a = b atomically with respect to previous value +! of a (a0). If *a==a0 then assign *a to b, all in one atomic operation. +! Returns 1 if assignment happened, and 0 otherwise. +! +! usage : old_val = compare_and_swap(address, oldval, newval) +! +! ----------------------- +! Note on REGISTER USAGE: +! as this is a LEAF procedure, a new stack frame is not created; +! we use the caller stack frame so what would normally be %i (input) +! registers are actually %o (output registers). Also, we must not +! overwrite the contents of %l (local) registers as they are not +! assumed to be volatile during calls. +! +! So, the registers used are: +! %o0 [input] - the address of the value to increment +! %o1 [input] - the old value to compare with +! %o2 [input] - the new value to set for [%o0] +! %o3 [local] - work register +! ----------------------- +#ifndef ULTRA_SPARC +! v8 + + ENTRY(compare_and_swap) ! standard assembler/ELF prologue + + stbar + mov -1,%o3 ! busy flag + swap [%o0],%o3 ! get current value +l1: cmp %o3,-1 ! busy? + be,a l1 ! if so, spin + swap [%o0],%o3 ! using branch-delay to swap back value + cmp %o1,%o3 ! compare old with current + be,a l2 ! if equal then swap in new value + swap [%o0],%o2 ! done. + swap [%o0],%o3 ! otherwise, swap back current value + retl + mov 0,%o0 ! return false +l2: retl + mov 1,%o0 ! return true + + SET_SIZE(compare_and_swap) ! standard assembler/ELF epilogue + +! +! end +! +#else /* ULTRA_SPARC */ +! ====================================================================== +! +! v9 + + ENTRY(compare_and_swap) ! standard assembler/ELF prologue + + stbar + cas [%o0],%o1,%o2 ! compare *w with old value and set to new if equal + cmp %o1,%o2 ! did we succeed? + be,a m1 ! yes + mov 1,%o0 ! return true (annulled when no jump) + mov 0,%o0 ! return false +m1: retl + nop + + SET_SIZE(compare_and_swap) ! standard assembler/ELF epilogue + +! +! end +! +! ====================================================================== +! +#endif |