[uclibc-ng-devel] [PATCH] xtensa: relax memory constraint in atomic assembly

Replace "a" constraints with "+m" to avoid forcing atomic variable address into a register and let the compiler use non-zero offset in load/store opcodes. Signed-off-by: Max Filippov <jcmvbkbc(a)gmail.com> --- libc/sysdeps/linux/xtensa/bits/atomic.h | 49 +++++++++---------- .../linuxthreads/sysdeps/xtensa/pt-machine.h | 15 +++--- 2 files changed, 31 insertions(+), 33 deletions(-) diff --git a/libc/sysdeps/linux/xtensa/bits/atomic.h b/libc/sysdeps/linux/xtensa/bits/atomic.h index b2be547f03e9..efc027d1ac25 100644 --- a/libc/sysdeps/linux/xtensa/bits/atomic.h +++ b/libc/sysdeps/linux/xtensa/bits/atomic.h @@ -56,16 +56,16 @@ typedef uintmax_t uatomic_max_t; #define __arch_compare_and_exchange_val_32_acq(mem, newval, oldval) \ ({__typeof__(*(mem)) __tmp, __value; \ __asm__ __volatile__( \ - "1: l32i %1, %2, 0 \n" \ + "1: l32i %1, %2 \n" \ " bne %1, %4, 2f \n" \ " wsr %1, SCOMPARE1 \n" \ " mov %0, %1 \n" \ " mov %1, %3 \n" \ - " s32c1i %1, %2, 0 \n" \ + " s32c1i %1, %2 \n" \ " bne %0, %1, 1b \n" \ "2: \n" \ - : "=&a" (__value), "=&a" (__tmp) \ - : "a" (mem), "a" (newval), "a" (oldval) \ + : "=&a" (__value), "=&a" (__tmp), "+m" (*(mem)) \ + : "a" (newval), "a" (oldval) \ : "memory" ); \ __tmp; \ }) @@ -76,17 +76,17 @@ typedef uintmax_t uatomic_max_t; #define __arch_compare_and_exchange_bool_32_acq(mem, newval, oldval) \ ({__typeof__(*(mem)) __tmp, __value; \ __asm__ __volatile__( \ - "1: l32i %0, %2, 0 \n" \ + "1: l32i %0, %2 \n" \ " sub %1, %4, %0 \n" \ " bnez %1, 2f \n" \ " wsr %0, SCOMPARE1 \n" \ " mov %1, %3 \n" \ - " s32c1i %1, %2, 0 \n" \ + " s32c1i %1, %2 \n" \ " bne %0, %1, 1b \n" \ " movi %1, 0 \n" \ "2: \n" \ - : "=&a" (__value), "=&a" (__tmp) \ - : "a" (mem), "a" (newval), "a" (oldval) \ + : "=&a" (__value), "=&a" (__tmp), "+m" (*(mem)) \ + : "a" (newval), "a" (oldval) \ : "memory" ); \ __tmp != 0; \ }) @@ -96,13 +96,13 @@ typedef uintmax_t uatomic_max_t; #define __arch_exchange_32_acq(mem, newval) \ ({__typeof__(*(mem)) __tmp, __value; \ __asm__ __volatile__( \ - "1: l32i %0, %2, 0 \n" \ + "1: l32i %0, %2 \n" \ " wsr %0, SCOMPARE1 \n" \ " mov %1, %3 \n" \ - " s32c1i %1, %2, 0 \n" \ + " s32c1i %1, %2 \n" \ " bne %0, %1, 1b \n" \ - : "=&a" (__value), "=&a" (__tmp) \ - : "a" (mem), "a" (newval) \ + : "=&a" (__value), "=&a" (__tmp), "+m" (*(mem)) \ + : "a" (newval) \ : "memory" ); \ __tmp; \ }) @@ -112,13 +112,13 @@ typedef uintmax_t uatomic_max_t; #define __arch_atomic_exchange_and_add_32(mem, value) \ ({__typeof__(*(mem)) __tmp, __value; \ __asm__ __volatile__( \ - "1: l32i %0, %2, 0 \n" \ + "1: l32i %0, %2 \n" \ " wsr %0, SCOMPARE1 \n" \ " add %1, %0, %3 \n" \ - " s32c1i %1, %2, 0 \n" \ + " s32c1i %1, %2 \n" \ " bne %0, %1, 1b \n" \ - : "=&a" (__value), "=&a" (__tmp) \ - : "a" (mem), "a" (value) \ + : "=&a" (__value), "=&a" (__tmp), "+m" (*(mem)) \ + : "a" (value) \ : "memory" ); \ __tmp; \ }) @@ -128,13 +128,13 @@ typedef uintmax_t uatomic_max_t; #define __arch_atomic_exchange_and_sub_32(mem, value) \ ({__typeof__(*(mem)) __tmp, __value; \ __asm__ __volatile__( \ - "1: l32i %0, %2, 0 \n" \ + "1: l32i %0, %2 \n" \ " wsr %0, SCOMPARE1 \n" \ " sub %1, %0, %3 \n" \ - " s32c1i %1, %2, 0 \n" \ + " s32c1i %1, %2 \n" \ " bne %0, %1, 1b \n" \ - : "=&a" (__value), "=&a" (__tmp) \ - : "a" (mem), "a" (value) \ + : "=&a" (__value), "=&a" (__tmp), "+m" (*(mem)) \ + : "a" (value) \ : "memory" ); \ __tmp; \ }) @@ -144,16 +144,15 @@ typedef uintmax_t uatomic_max_t; #define __arch_atomic_decrement_if_positive_32(mem) \ ({__typeof__(*(mem)) __tmp, __value; \ __asm__ __volatile__( \ - "1: l32i %0, %2, 0 \n" \ + "1: l32i %0, %2 \n" \ " blti %0, 1, 2f \n" \ " wsr %0, SCOMPARE1 \n" \ " addi %1, %0, -1 \n" \ - " s32c1i %1, %2, 0 \n" \ + " s32c1i %1, %2 \n" \ " bne %0, %1, 1b \n" \ "2: \n" \ - : "=&a" (__value), "=&a" (__tmp) \ - : "a" (mem) \ - : "memory" ); \ + : "=&a" (__value), "=&a" (__tmp), "+m" (*(mem)) \ + :: "memory" ); \ __value; \ }) diff --git a/libpthread/linuxthreads/sysdeps/xtensa/pt-machine.h b/libpthread/linuxthreads/sysdeps/xtensa/pt-machine.h index 2c68ddfb5fe1..82d9b540c611 100644 --- a/libpthread/linuxthreads/sysdeps/xtensa/pt-machine.h +++ b/libpthread/linuxthreads/sysdeps/xtensa/pt-machine.h @@ -43,10 +43,9 @@ testandset (int *spinlock) " movi %0, 0 \n" " wsr %0, SCOMPARE1 \n" " movi %0, 1 \n" -" s32c1i %0, %1, 0 \n" - : "=&a" (tmp) - : "a" (spinlock) - : "memory" +" s32c1i %0, %1 \n" + : "=&a" (tmp), "+m" (*spinlock) + :: "memory" ); return tmp; } @@ -57,16 +56,16 @@ __compare_and_swap (long int *p, long int oldval, long int newval) unsigned long tmp; unsigned long value; __asm__ volatile ( -"1: l32i %0, %2, 0 \n" +"1: l32i %0, %2 \n" " bne %0, %4, 2f \n" " wsr %0, SCOMPARE1 \n" " mov %1, %0 \n" " mov %0, %3 \n" -" s32c1i %0, %2, 0 \n" +" s32c1i %0, %2 \n" " bne %1, %0, 1b \n" "2: \n" - : "=&a" (tmp), "=&a" (value) - : "a" (p), "a" (newval), "a" (oldval) + : "=&a" (tmp), "=&a" (value), "+m" (*p) + : "a" (newval), "a" (oldval) : "memory" ); return tmp == oldval; -- 2.20.1