From 4561569a11353688b97220be8d6a0821d53b97a6 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Tue, 26 Apr 2016 13:47:21 +0200 Subject: [PATCH] x86/HVM: slightly improve hvm_mmio_{first,last}_byte() EFLAGS.DF can be assumed to be usually clear, so unlikely()-annotate the conditionals accordingly. Also prefer latching p->size (used twice) into a local variable, at once making it unnecessary for the reader to be sure expressions get evaluated left to right (operand promotion would yield a different result if p->addr + p->size - 1 was evaluted right to left). Signed-off-by: Jan Beulich Reviewed-by: Paul Durrant Release-acked-by: Wei Liu --- xen/include/asm-x86/hvm/io.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/xen/include/asm-x86/hvm/io.h b/xen/include/asm-x86/hvm/io.h index ceefa2ec92..5445fce168 100644 --- a/xen/include/asm-x86/hvm/io.h +++ b/xen/include/asm-x86/hvm/io.h @@ -44,18 +44,18 @@ struct hvm_mmio_ops { static inline paddr_t hvm_mmio_first_byte(const ioreq_t *p) { - return p->df ? + return unlikely(p->df) ? p->addr - (p->count - 1ul) * p->size : p->addr; } static inline paddr_t hvm_mmio_last_byte(const ioreq_t *p) { - unsigned long count = p->count; + unsigned long size = p->size; - return p->df ? - p->addr + p->size - 1: - p->addr + (count * p->size) - 1; + return unlikely(p->df) ? + p->addr + size - 1: + p->addr + (p->count * size) - 1; } typedef int (*portio_action_t)( -- 2.30.2