diff options
author | David Gibson <david@gibson.dropbear.id.au> | 2006-01-13 03:56:25 (GMT) |
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committer | Paul Mackerras <paulus@samba.org> | 2006-01-13 10:16:23 (GMT) |
commit | e58c3495e6007af59382540bb21ee941e470d88d (patch) | |
tree | 24b559cb768bfa5cf4bdef69f2943b081a1f5afa /include/asm-powerpc | |
parent | 7e78e5e502d4f220d24c6f738f2fdb078ad33607 (diff) | |
download | linux-e58c3495e6007af59382540bb21ee941e470d88d.tar.xz |
[PATCH] powerpc: Cleanup LOADADDR etc. asm macros
This patch consolidates the variety of macros used for loading 32 or
64-bit constants in assembler (LOADADDR, LOADBASE, SET_REG_TO_*). The
idea is to make the set of macros consistent across 32 and 64 bit and
to make it more obvious which is the appropriate one to use in a given
situation. The new macros and their semantics are described in the
comments in ppc_asm.h.
In the process, we change several places that were unnecessarily using
immediate loads on ppc64 to use the GOT/TOC. Likewise we cleanup a
couple of places where we were clumsily subtracting PAGE_OFFSET with
asm instructions to use assemble-time arithmetic or the toreal() macro
instead.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'include/asm-powerpc')
-rw-r--r-- | include/asm-powerpc/ppc_asm.h | 76 |
1 files changed, 40 insertions, 36 deletions
diff --git a/include/asm-powerpc/ppc_asm.h b/include/asm-powerpc/ppc_asm.h index 0dc798d..ab8688d 100644 --- a/include/asm-powerpc/ppc_asm.h +++ b/include/asm-powerpc/ppc_asm.h @@ -156,52 +156,56 @@ n: #endif /* - * LOADADDR( rn, name ) - * loads the address of 'name' into 'rn' + * LOAD_REG_IMMEDIATE(rn, expr) + * Loads the value of the constant expression 'expr' into register 'rn' + * using immediate instructions only. Use this when it's important not + * to reference other data (i.e. on ppc64 when the TOC pointer is not + * valid). * - * LOADBASE( rn, name ) - * loads the address (possibly without the low 16 bits) of 'name' into 'rn' - * suitable for base+disp addressing + * LOAD_REG_ADDR(rn, name) + * Loads the address of label 'name' into register 'rn'. Use this when + * you don't particularly need immediate instructions only, but you need + * the whole address in one register (e.g. it's a structure address and + * you want to access various offsets within it). On ppc32 this is + * identical to LOAD_REG_IMMEDIATE. + * + * LOAD_REG_ADDRBASE(rn, name) + * ADDROFF(name) + * LOAD_REG_ADDRBASE loads part of the address of label 'name' into + * register 'rn'. ADDROFF(name) returns the remainder of the address as + * a constant expression. ADDROFF(name) is a signed expression < 16 bits + * in size, so is suitable for use directly as an offset in load and store + * instructions. Use this when loading/storing a single word or less as: + * LOAD_REG_ADDRBASE(rX, name) + * ld rY,ADDROFF(name)(rX) */ #ifdef __powerpc64__ -#define LOADADDR(rn,name) \ - lis rn,name##@highest; \ - ori rn,rn,name##@higher; \ - rldicr rn,rn,32,31; \ - oris rn,rn,name##@h; \ - ori rn,rn,name##@l - -#define LOADBASE(rn,name) \ - ld rn,name@got(r2) - -#define OFF(name) 0 - -#define SET_REG_TO_CONST(reg, value) \ - lis reg,(((value)>>48)&0xFFFF); \ - ori reg,reg,(((value)>>32)&0xFFFF); \ - rldicr reg,reg,32,31; \ - oris reg,reg,(((value)>>16)&0xFFFF); \ - ori reg,reg,((value)&0xFFFF); - -#define SET_REG_TO_LABEL(reg, label) \ - lis reg,(label)@highest; \ - ori reg,reg,(label)@higher; \ - rldicr reg,reg,32,31; \ - oris reg,reg,(label)@h; \ - ori reg,reg,(label)@l; +#define LOAD_REG_IMMEDIATE(reg,expr) \ + lis (reg),(expr)@highest; \ + ori (reg),(reg),(expr)@higher; \ + rldicr (reg),(reg),32,31; \ + oris (reg),(reg),(expr)@h; \ + ori (reg),(reg),(expr)@l; + +#define LOAD_REG_ADDR(reg,name) \ + ld (reg),name@got(r2) + +#define LOAD_REG_ADDRBASE(reg,name) LOAD_REG_ADDR(reg,name) +#define ADDROFF(name) 0 /* offsets for stack frame layout */ #define LRSAVE 16 #else /* 32-bit */ -#define LOADADDR(rn,name) \ - lis rn,name@ha; \ - addi rn,rn,name@l -#define LOADBASE(rn,name) \ - lis rn,name@ha +#define LOAD_REG_IMMEDIATE(reg,expr) \ + lis (reg),(expr)@ha; \ + addi (reg),(reg),(expr)@l; + +#define LOAD_REG_ADDR(reg,name) LOAD_REG_IMMEDIATE(reg, name) -#define OFF(name) name@l +#define LOAD_REG_ADDRBASE(reg, name) lis (reg),name@ha +#define ADDROFF(name) name@l /* offsets for stack frame layout */ #define LRSAVE 4 |