Date: Mon, 17 Sep 2018 18:45:16 +0000 (UTC) From: John Baldwin <jhb@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org Subject: svn commit: r338727 - stable/11/sys/amd64/include Message-ID: <201809171845.w8HIjG1u043200@repo.freebsd.org>
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Author: jhb Date: Mon Sep 17 18:45:16 2018 New Revision: 338727 URL: https://svnweb.freebsd.org/changeset/base/338727 Log: MFC 335913: Use 'e' instead of 'i' constraints with 64-bit atomic operations on amd64. The ADD, AND, OR, and SUB instructions take at most a 32-bit sign-extended immediate operand. 64-bit constants that do not fit into that constraint need to be loaded into a register. The 'i' constraint tells the compiler it can pass any integer constant to the assembler, whereas the 'e' constrain only permits constants that fit into a 32-bit sign-extended value. This fixes using atomic_add/clear/set/subtract_long/64 with constants that do not fit into a 32-bit sign-extended immediate. Modified: stable/11/sys/amd64/include/atomic.h Directory Properties: stable/11/ (props changed) Modified: stable/11/sys/amd64/include/atomic.h ============================================================================== --- stable/11/sys/amd64/include/atomic.h Mon Sep 17 18:36:29 2018 (r338726) +++ stable/11/sys/amd64/include/atomic.h Mon Sep 17 18:45:16 2018 (r338727) @@ -444,10 +444,10 @@ ATOMIC_ASM(clear, int, "andl %1,%0", "ir", ~v); ATOMIC_ASM(add, int, "addl %1,%0", "ir", v); ATOMIC_ASM(subtract, int, "subl %1,%0", "ir", v); -ATOMIC_ASM(set, long, "orq %1,%0", "ir", v); -ATOMIC_ASM(clear, long, "andq %1,%0", "ir", ~v); -ATOMIC_ASM(add, long, "addq %1,%0", "ir", v); -ATOMIC_ASM(subtract, long, "subq %1,%0", "ir", v); +ATOMIC_ASM(set, long, "orq %1,%0", "er", v); +ATOMIC_ASM(clear, long, "andq %1,%0", "er", ~v); +ATOMIC_ASM(add, long, "addq %1,%0", "er", v); +ATOMIC_ASM(subtract, long, "subq %1,%0", "er", v); #define ATOMIC_LOADSTORE(TYPE) \ ATOMIC_LOAD(TYPE); \
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