[PATCH 7/8] atomic: Switch power to builtin atomics
Wilco Dijkstra
Wilco.Dijkstra@arm.com
Tue Sep 9 11:21:22 GMT 2025
Switch power to builtin atomics.
Passes buildmanyglibc, OK for commit?
---
diff --git a/sysdeps/powerpc/atomic-machine.h b/sysdeps/powerpc/atomic-machine.h
index f5624572d8bef4baa6b46e893277bfbc1c3511a0..12f4b782222944d10650d8255a01dd2bc4d8ce60 100644
--- a/sysdeps/powerpc/atomic-machine.h
+++ b/sysdeps/powerpc/atomic-machine.h
@@ -25,16 +25,6 @@
* as appropriate and which in turn include this file.
*/
-/*
- * Powerpc does not have byte and halfword forms of load and reserve and
- * store conditional. So for powerpc we stub out the 8- and 16-bit forms.
- */
-#define __arch_compare_and_exchange_bool_8_acq(mem, newval, oldval) \
- (abort (), 0)
-
-#define __arch_compare_and_exchange_bool_16_acq(mem, newval, oldval) \
- (abort (), 0)
-
#define __ARCH_ACQ_INSTR "isync"
#ifndef __ARCH_REL_INSTR
# define __ARCH_REL_INSTR "sync"
@@ -49,268 +39,3 @@
#define atomic_full_barrier() __asm ("sync" ::: "memory")
-#define __arch_compare_and_exchange_val_32_acq(mem, newval, oldval) \
- ({ \
- __typeof (*(mem)) __tmp; \
- __typeof (mem) __memp = (mem); \
- __asm __volatile ( \
- "1: lwarx %0,0,%1" MUTEX_HINT_ACQ "\n" \
- " cmpw %0,%2\n" \
- " bne 2f\n" \
- " stwcx. %3,0,%1\n" \
- " bne- 1b\n" \
- "2: " __ARCH_ACQ_INSTR \
- : "=&r" (__tmp) \
- : "b" (__memp), "r" (oldval), "r" (newval) \
- : "cr0", "memory"); \
- __tmp; \
- })
-
-#define __arch_compare_and_exchange_val_32_rel(mem, newval, oldval) \
- ({ \
- __typeof (*(mem)) __tmp; \
- __typeof (mem) __memp = (mem); \
- __asm __volatile (__ARCH_REL_INSTR "\n" \
- "1: lwarx %0,0,%1" MUTEX_HINT_REL "\n" \
- " cmpw %0,%2\n" \
- " bne 2f\n" \
- " stwcx. %3,0,%1\n" \
- " bne- 1b\n" \
- "2: " \
- : "=&r" (__tmp) \
- : "b" (__memp), "r" (oldval), "r" (newval) \
- : "cr0", "memory"); \
- __tmp; \
- })
-
-#define __arch_atomic_exchange_32_acq(mem, value) \
- ({ \
- __typeof (*mem) __val; \
- __asm __volatile ( \
- "1: lwarx %0,0,%2" MUTEX_HINT_ACQ "\n" \
- " stwcx. %3,0,%2\n" \
- " bne- 1b\n" \
- " " __ARCH_ACQ_INSTR \
- : "=&r" (__val), "=m" (*mem) \
- : "b" (mem), "r" (value), "m" (*mem) \
- : "cr0", "memory"); \
- __val; \
- })
-
-#define __arch_atomic_exchange_32_rel(mem, value) \
- ({ \
- __typeof (*mem) __val; \
- __asm __volatile (__ARCH_REL_INSTR "\n" \
- "1: lwarx %0,0,%2" MUTEX_HINT_REL "\n" \
- " stwcx. %3,0,%2\n" \
- " bne- 1b" \
- : "=&r" (__val), "=m" (*mem) \
- : "b" (mem), "r" (value), "m" (*mem) \
- : "cr0", "memory"); \
- __val; \
- })
-
-#define __arch_atomic_exchange_and_add_32(mem, value) \
- ({ \
- __typeof (*mem) __val, __tmp; \
- __asm __volatile ("1: lwarx %0,0,%3\n" \
- " add %1,%0,%4\n" \
- " stwcx. %1,0,%3\n" \
- " bne- 1b" \
- : "=&b" (__val), "=&r" (__tmp), "=m" (*mem) \
- : "b" (mem), "r" (value), "m" (*mem) \
- : "cr0", "memory"); \
- __val; \
- })
-
-#define __arch_atomic_exchange_and_add_32_acq(mem, value) \
- ({ \
- __typeof (*mem) __val, __tmp; \
- __asm __volatile ("1: lwarx %0,0,%3" MUTEX_HINT_ACQ "\n" \
- " add %1,%0,%4\n" \
- " stwcx. %1,0,%3\n" \
- " bne- 1b\n" \
- __ARCH_ACQ_INSTR \
- : "=&b" (__val), "=&r" (__tmp), "=m" (*mem) \
- : "b" (mem), "r" (value), "m" (*mem) \
- : "cr0", "memory"); \
- __val; \
- })
-
-#define __arch_atomic_exchange_and_add_32_rel(mem, value) \
- ({ \
- __typeof (*mem) __val, __tmp; \
- __asm __volatile (__ARCH_REL_INSTR "\n" \
- "1: lwarx %0,0,%3" MUTEX_HINT_REL "\n" \
- " add %1,%0,%4\n" \
- " stwcx. %1,0,%3\n" \
- " bne- 1b" \
- : "=&b" (__val), "=&r" (__tmp), "=m" (*mem) \
- : "b" (mem), "r" (value), "m" (*mem) \
- : "cr0", "memory"); \
- __val; \
- })
-
-#define __arch_atomic_increment_val_32(mem) \
- ({ \
- __typeof (*(mem)) __val; \
- __asm __volatile ("1: lwarx %0,0,%2\n" \
- " addi %0,%0,1\n" \
- " stwcx. %0,0,%2\n" \
- " bne- 1b" \
- : "=&b" (__val), "=m" (*mem) \
- : "b" (mem), "m" (*mem) \
- : "cr0", "memory"); \
- __val; \
- })
-
-#define __arch_atomic_decrement_val_32(mem) \
- ({ \
- __typeof (*(mem)) __val; \
- __asm __volatile ("1: lwarx %0,0,%2\n" \
- " subi %0,%0,1\n" \
- " stwcx. %0,0,%2\n" \
- " bne- 1b" \
- : "=&b" (__val), "=m" (*mem) \
- : "b" (mem), "m" (*mem) \
- : "cr0", "memory"); \
- __val; \
- })
-
-#define __arch_atomic_decrement_if_positive_32(mem) \
- ({ int __val, __tmp; \
- __asm __volatile ("1: lwarx %0,0,%3\n" \
- " cmpwi 0,%0,0\n" \
- " addi %1,%0,-1\n" \
- " ble 2f\n" \
- " stwcx. %1,0,%3\n" \
- " bne- 1b\n" \
- "2: " __ARCH_ACQ_INSTR \
- : "=&b" (__val), "=&r" (__tmp), "=m" (*mem) \
- : "b" (mem), "m" (*mem) \
- : "cr0", "memory"); \
- __val; \
- })
-
-#define atomic_compare_and_exchange_val_acq(mem, newval, oldval) \
- ({ \
- __typeof (*(mem)) __result; \
- if (sizeof (*mem) == 4) \
- __result = __arch_compare_and_exchange_val_32_acq(mem, newval, oldval); \
- else if (sizeof (*mem) == 8) \
- __result = __arch_compare_and_exchange_val_64_acq(mem, newval, oldval); \
- else \
- abort (); \
- __result; \
- })
-
-#define atomic_compare_and_exchange_val_rel(mem, newval, oldval) \
- ({ \
- __typeof (*(mem)) __result; \
- if (sizeof (*mem) == 4) \
- __result = __arch_compare_and_exchange_val_32_rel(mem, newval, oldval); \
- else if (sizeof (*mem) == 8) \
- __result = __arch_compare_and_exchange_val_64_rel(mem, newval, oldval); \
- else \
- abort (); \
- __result; \
- })
-
-#define atomic_exchange_acq(mem, value) \
- ({ \
- __typeof (*(mem)) __result; \
- if (sizeof (*mem) == 4) \
- __result = __arch_atomic_exchange_32_acq (mem, value); \
- else if (sizeof (*mem) == 8) \
- __result = __arch_atomic_exchange_64_acq (mem, value); \
- else \
- abort (); \
- __result; \
- })
-
-#define atomic_exchange_rel(mem, value) \
- ({ \
- __typeof (*(mem)) __result; \
- if (sizeof (*mem) == 4) \
- __result = __arch_atomic_exchange_32_rel (mem, value); \
- else if (sizeof (*mem) == 8) \
- __result = __arch_atomic_exchange_64_rel (mem, value); \
- else \
- abort (); \
- __result; \
- })
-
-#define atomic_exchange_and_add(mem, value) \
- ({ \
- __typeof (*(mem)) __result; \
- if (sizeof (*mem) == 4) \
- __result = __arch_atomic_exchange_and_add_32 (mem, value); \
- else if (sizeof (*mem) == 8) \
- __result = __arch_atomic_exchange_and_add_64 (mem, value); \
- else \
- abort (); \
- __result; \
- })
-#define atomic_exchange_and_add_acq(mem, value) \
- ({ \
- __typeof (*(mem)) __result; \
- if (sizeof (*mem) == 4) \
- __result = __arch_atomic_exchange_and_add_32_acq (mem, value); \
- else if (sizeof (*mem) == 8) \
- __result = __arch_atomic_exchange_and_add_64_acq (mem, value); \
- else \
- abort (); \
- __result; \
- })
-#define atomic_exchange_and_add_rel(mem, value) \
- ({ \
- __typeof (*(mem)) __result; \
- if (sizeof (*mem) == 4) \
- __result = __arch_atomic_exchange_and_add_32_rel (mem, value); \
- else if (sizeof (*mem) == 8) \
- __result = __arch_atomic_exchange_and_add_64_rel (mem, value); \
- else \
- abort (); \
- __result; \
- })
-
-#define atomic_increment_val(mem) \
- ({ \
- __typeof (*(mem)) __result; \
- if (sizeof (*(mem)) == 4) \
- __result = __arch_atomic_increment_val_32 (mem); \
- else if (sizeof (*(mem)) == 8) \
- __result = __arch_atomic_increment_val_64 (mem); \
- else \
- abort (); \
- __result; \
- })
-
-#define atomic_increment(mem) ({ atomic_increment_val (mem); (void) 0; })
-
-#define atomic_decrement_val(mem) \
- ({ \
- __typeof (*(mem)) __result; \
- if (sizeof (*(mem)) == 4) \
- __result = __arch_atomic_decrement_val_32 (mem); \
- else if (sizeof (*(mem)) == 8) \
- __result = __arch_atomic_decrement_val_64 (mem); \
- else \
- abort (); \
- __result; \
- })
-
-#define atomic_decrement(mem) ({ atomic_decrement_val (mem); (void) 0; })
-
-
-/* Decrement *MEM if it is > 0, and return the old value. */
-#define atomic_decrement_if_positive(mem) \
- ({ __typeof (*(mem)) __result; \
- if (sizeof (*mem) == 4) \
- __result = __arch_atomic_decrement_if_positive_32 (mem); \
- else if (sizeof (*mem) == 8) \
- __result = __arch_atomic_decrement_if_positive_64 (mem); \
- else \
- abort (); \
- __result; \
- })
diff --git a/sysdeps/powerpc/powerpc32/atomic-machine.h b/sysdeps/powerpc/powerpc32/atomic-machine.h
index 4534f307407d557d011f4c5811d106817fbc03ba..2e9860cb9da5423621dc6da21a5876b4e74e65bb 100644
--- a/sysdeps/powerpc/powerpc32/atomic-machine.h
+++ b/sysdeps/powerpc/powerpc32/atomic-machine.h
@@ -33,67 +33,9 @@
#endif
#define __HAVE_64B_ATOMICS 0
-#define USE_ATOMIC_COMPILER_BUILTINS 0
+#define USE_ATOMIC_COMPILER_BUILTINS 1
#define ATOMIC_EXCHANGE_USES_CAS 1
-/*
- * The 32-bit exchange_bool is different on powerpc64 because the subf
- * does signed 64-bit arithmetic while the lwarx is 32-bit unsigned
- * (a load word and zero (high 32) form). So powerpc64 has a slightly
- * different version in sysdeps/powerpc/powerpc64/atomic-machine.h.
- */
-#define __arch_compare_and_exchange_bool_32_acq(mem, newval, oldval) \
-({ \
- unsigned int __tmp; \
- __asm __volatile ( \
- "1: lwarx %0,0,%1" MUTEX_HINT_ACQ "\n" \
- " subf. %0,%2,%0\n" \
- " bne 2f\n" \
- " stwcx. %3,0,%1\n" \
- " bne- 1b\n" \
- "2: " __ARCH_ACQ_INSTR \
- : "=&r" (__tmp) \
- : "b" (mem), "r" (oldval), "r" (newval) \
- : "cr0", "memory"); \
- __tmp != 0; \
-})
-
-/* Powerpc32 processors don't implement the 64-bit (doubleword) forms of
- load and reserve (ldarx) and store conditional (stdcx.) instructions.
- So for powerpc32 we stub out the 64-bit forms. */
-#define __arch_compare_and_exchange_bool_64_acq(mem, newval, oldval) \
- (abort (), 0)
-
-#define __arch_compare_and_exchange_val_64_acq(mem, newval, oldval) \
- (abort (), (__typeof (*mem)) 0)
-
-#define __arch_compare_and_exchange_val_64_rel(mem, newval, oldval) \
- (abort (), (__typeof (*mem)) 0)
-
-#define __arch_atomic_exchange_64_acq(mem, value) \
- ({ abort (); (*mem) = (value); })
-
-#define __arch_atomic_exchange_64_rel(mem, value) \
- ({ abort (); (*mem) = (value); })
-
-#define __arch_atomic_exchange_and_add_64(mem, value) \
- ({ abort (); (*mem) = (value); })
-
-#define __arch_atomic_exchange_and_add_64_acq(mem, value) \
- ({ abort (); (*mem) = (value); })
-
-#define __arch_atomic_exchange_and_add_64_rel(mem, value) \
- ({ abort (); (*mem) = (value); })
-
-#define __arch_atomic_increment_val_64(mem) \
- ({ abort (); (*mem)++; })
-
-#define __arch_atomic_decrement_val_64(mem) \
- ({ abort (); (*mem)--; })
-
-#define __arch_atomic_decrement_if_positive_64(mem) \
- ({ abort (); (*mem)--; })
-
#ifdef _ARCH_PWR4
/*
* Newer powerpc64 processors support the new "light weight" sync (lwsync)
diff --git a/sysdeps/powerpc/powerpc64/atomic-machine.h b/sysdeps/powerpc/powerpc64/atomic-machine.h
index 3754b55dda0ad554f05ebf9cfdb105bcaabbd89e..9ae48a907d8e71eea0c2b06fd95645893210427e 100644
--- a/sysdeps/powerpc/powerpc64/atomic-machine.h
+++ b/sysdeps/powerpc/powerpc64/atomic-machine.h
@@ -33,195 +33,9 @@
#endif
#define __HAVE_64B_ATOMICS 1
-#define USE_ATOMIC_COMPILER_BUILTINS 0
+#define USE_ATOMIC_COMPILER_BUILTINS 1
#define ATOMIC_EXCHANGE_USES_CAS 1
-/* The 32-bit exchange_bool is different on powerpc64 because the subf
- does signed 64-bit arithmetic while the lwarx is 32-bit unsigned
- (a load word and zero (high 32) form) load.
- In powerpc64 register values are 64-bit by default, including oldval.
- The value in old val unknown sign extension, lwarx loads the 32-bit
- value as unsigned. So we explicitly clear the high 32 bits in oldval. */
-#define __arch_compare_and_exchange_bool_32_acq(mem, newval, oldval) \
-({ \
- unsigned int __tmp, __tmp2; \
- __asm __volatile (" clrldi %1,%1,32\n" \
- "1: lwarx %0,0,%2" MUTEX_HINT_ACQ "\n" \
- " subf. %0,%1,%0\n" \
- " bne 2f\n" \
- " stwcx. %4,0,%2\n" \
- " bne- 1b\n" \
- "2: " __ARCH_ACQ_INSTR \
- : "=&r" (__tmp), "=r" (__tmp2) \
- : "b" (mem), "1" (oldval), "r" (newval) \
- : "cr0", "memory"); \
- __tmp != 0; \
-})
-
-/*
- * Only powerpc64 processors support Load doubleword and reserve index (ldarx)
- * and Store doubleword conditional indexed (stdcx) instructions. So here
- * we define the 64-bit forms.
- */
-#define __arch_compare_and_exchange_bool_64_acq(mem, newval, oldval) \
-({ \
- unsigned long __tmp; \
- __asm __volatile ( \
- "1: ldarx %0,0,%1" MUTEX_HINT_ACQ "\n" \
- " subf. %0,%2,%0\n" \
- " bne 2f\n" \
- " stdcx. %3,0,%1\n" \
- " bne- 1b\n" \
- "2: " __ARCH_ACQ_INSTR \
- : "=&r" (__tmp) \
- : "b" (mem), "r" (oldval), "r" (newval) \
- : "cr0", "memory"); \
- __tmp != 0; \
-})
-
-#define __arch_compare_and_exchange_val_64_acq(mem, newval, oldval) \
- ({ \
- __typeof (*(mem)) __tmp; \
- __typeof (mem) __memp = (mem); \
- __asm __volatile ( \
- "1: ldarx %0,0,%1" MUTEX_HINT_ACQ "\n" \
- " cmpd %0,%2\n" \
- " bne 2f\n" \
- " stdcx. %3,0,%1\n" \
- " bne- 1b\n" \
- "2: " __ARCH_ACQ_INSTR \
- : "=&r" (__tmp) \
- : "b" (__memp), "r" (oldval), "r" (newval) \
- : "cr0", "memory"); \
- __tmp; \
- })
-
-#define __arch_compare_and_exchange_val_64_rel(mem, newval, oldval) \
- ({ \
- __typeof (*(mem)) __tmp; \
- __typeof (mem) __memp = (mem); \
- __asm __volatile (__ARCH_REL_INSTR "\n" \
- "1: ldarx %0,0,%1" MUTEX_HINT_REL "\n" \
- " cmpd %0,%2\n" \
- " bne 2f\n" \
- " stdcx. %3,0,%1\n" \
- " bne- 1b\n" \
- "2: " \
- : "=&r" (__tmp) \
- : "b" (__memp), "r" (oldval), "r" (newval) \
- : "cr0", "memory"); \
- __tmp; \
- })
-
-#define __arch_atomic_exchange_64_acq(mem, value) \
- ({ \
- __typeof (*mem) __val; \
- __asm __volatile (__ARCH_REL_INSTR "\n" \
- "1: ldarx %0,0,%2" MUTEX_HINT_ACQ "\n" \
- " stdcx. %3,0,%2\n" \
- " bne- 1b\n" \
- " " __ARCH_ACQ_INSTR \
- : "=&r" (__val), "=m" (*mem) \
- : "b" (mem), "r" (value), "m" (*mem) \
- : "cr0", "memory"); \
- __val; \
- })
-
-#define __arch_atomic_exchange_64_rel(mem, value) \
- ({ \
- __typeof (*mem) __val; \
- __asm __volatile (__ARCH_REL_INSTR "\n" \
- "1: ldarx %0,0,%2" MUTEX_HINT_REL "\n" \
- " stdcx. %3,0,%2\n" \
- " bne- 1b" \
- : "=&r" (__val), "=m" (*mem) \
- : "b" (mem), "r" (value), "m" (*mem) \
- : "cr0", "memory"); \
- __val; \
- })
-
-#define __arch_atomic_exchange_and_add_64(mem, value) \
- ({ \
- __typeof (*mem) __val, __tmp; \
- __asm __volatile ("1: ldarx %0,0,%3\n" \
- " add %1,%0,%4\n" \
- " stdcx. %1,0,%3\n" \
- " bne- 1b" \
- : "=&b" (__val), "=&r" (__tmp), "=m" (*mem) \
- : "b" (mem), "r" (value), "m" (*mem) \
- : "cr0", "memory"); \
- __val; \
- })
-
-#define __arch_atomic_exchange_and_add_64_acq(mem, value) \
- ({ \
- __typeof (*mem) __val, __tmp; \
- __asm __volatile ("1: ldarx %0,0,%3" MUTEX_HINT_ACQ "\n" \
- " add %1,%0,%4\n" \
- " stdcx. %1,0,%3\n" \
- " bne- 1b\n" \
- __ARCH_ACQ_INSTR \
- : "=&b" (__val), "=&r" (__tmp), "=m" (*mem) \
- : "b" (mem), "r" (value), "m" (*mem) \
- : "cr0", "memory"); \
- __val; \
- })
-
-#define __arch_atomic_exchange_and_add_64_rel(mem, value) \
- ({ \
- __typeof (*mem) __val, __tmp; \
- __asm __volatile (__ARCH_REL_INSTR "\n" \
- "1: ldarx %0,0,%3" MUTEX_HINT_REL "\n" \
- " add %1,%0,%4\n" \
- " stdcx. %1,0,%3\n" \
- " bne- 1b" \
- : "=&b" (__val), "=&r" (__tmp), "=m" (*mem) \
- : "b" (mem), "r" (value), "m" (*mem) \
- : "cr0", "memory"); \
- __val; \
- })
-
-#define __arch_atomic_increment_val_64(mem) \
- ({ \
- __typeof (*(mem)) __val; \
- __asm __volatile ("1: ldarx %0,0,%2\n" \
- " addi %0,%0,1\n" \
- " stdcx. %0,0,%2\n" \
- " bne- 1b" \
- : "=&b" (__val), "=m" (*mem) \
- : "b" (mem), "m" (*mem) \
- : "cr0", "memory"); \
- __val; \
- })
-
-#define __arch_atomic_decrement_val_64(mem) \
- ({ \
- __typeof (*(mem)) __val; \
- __asm __volatile ("1: ldarx %0,0,%2\n" \
- " subi %0,%0,1\n" \
- " stdcx. %0,0,%2\n" \
- " bne- 1b" \
- : "=&b" (__val), "=m" (*mem) \
- : "b" (mem), "m" (*mem) \
- : "cr0", "memory"); \
- __val; \
- })
-
-#define __arch_atomic_decrement_if_positive_64(mem) \
- ({ int __val, __tmp; \
- __asm __volatile ("1: ldarx %0,0,%3\n" \
- " cmpdi 0,%0,0\n" \
- " addi %1,%0,-1\n" \
- " ble 2f\n" \
- " stdcx. %1,0,%3\n" \
- " bne- 1b\n" \
- "2: " __ARCH_ACQ_INSTR \
- : "=&b" (__val), "=&r" (__tmp), "=m" (*mem) \
- : "b" (mem), "m" (*mem) \
- : "cr0", "memory"); \
- __val; \
- })
-
/*
* All powerpc64 processors support the new "light weight" sync (lwsync).
*/
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