From f0eb2e77b2132a88e2f00d8e06ffa7638c40b4bc Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Wed, 17 Jul 2019 19:07:57 -0400 Subject: [PATCH] use register constraint instead of memory operand for riscv64 atomics the "A" constraint is simply for an address expression that's a single register, but it's not yet supported by clang, and has no advantage here over just using a register operand for the address. the latter is actually preferable in the a_cas_p case because it avoids aliasing an lvalue onto the memory. --- arch/riscv64/atomic_arch.h | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/arch/riscv64/atomic_arch.h b/arch/riscv64/atomic_arch.h index d0228a3e..c9765342 100644 --- a/arch/riscv64/atomic_arch.h +++ b/arch/riscv64/atomic_arch.h @@ -9,13 +9,13 @@ static inline int a_cas(volatile int *p, int t, int s) { int old, tmp; __asm__ __volatile__ ( - "\n1: lr.w.aqrl %0, %2\n" + "\n1: lr.w.aqrl %0, (%2)\n" " bne %0, %3, 1f\n" - " sc.w.aqrl %1, %4, %2\n" + " sc.w.aqrl %1, %4, (%2)\n" " bnez %1, 1b\n" "1:" - : "=&r"(old), "=r"(tmp), "+A"(*p) - : "r"(t), "r"(s) + : "=&r"(old), "=r"(tmp) + : "r"(p), "r"(t), "r"(s) : "memory"); return old; } @@ -26,13 +26,13 @@ static inline void *a_cas_p(volatile void *p, void *t, void *s) void *old; int tmp; __asm__ __volatile__ ( - "\n1: lr.d.aqrl %0, %2\n" + "\n1: lr.d.aqrl %0, (%2)\n" " bne %0, %3, 1f\n" - " sc.d.aqrl %1, %4, %2\n" + " sc.d.aqrl %1, %4, (%2)\n" " bnez %1, 1b\n" "1:" - : "=&r"(old), "=r"(tmp), "+A"(*(long *)p) - : "r"(t), "r"(s) + : "=&r"(old), "=r"(tmp) + : "r"(p), "r"(t), "r"(s) : "memory"); return old; } -- 2.25.1