Clean up and optimize _dl_start a bit by using immediate addressing for

the constants whenever they fit, and avoiding saving and restoring
registers we don't need to preserve.

diff --git a/libexec/ld.so/sh/ldasm.S b/libexec/ld.so/sh/ldasm.S
index fed5cab..c258229 100644 (file)
--- a/libexec/ld.so/sh/ldasm.S
+++ b/libexec/ld.so/sh/ldasm.S
@@ -1,4 +1,4 @@
-/*     $OpenBSD: ldasm.S,v 1.17 2014/07/14 03:54:51 deraadt Exp $ */
+/*     $OpenBSD: ldasm.S,v 1.18 2014/12/30 18:31:21 miod Exp $ */
 
 /*
  * Copyright (c) 2006 Dale Rahn
@@ -32,59 +32,45 @@
 #include <SYS.h>
 
 ENTRY(_dl_start)
-       mov     r15, r12                        // save for later 
-       sts     pr, r11
-       mov     r15, r4                 // boot_bind(sp, dl_data) (sp)
-       mov.l   .L_datasize, r0
-       sub     r0, r15
-       mov     r15, r5
-       mov     r5, r13
-       // not trusting register to store the data, push it on the stack.
-       // callee/caller save questions
-
-       mov     r15, r14
-
+       mov     r15, r12                // save for later 
+       mov     r15, r4                 // sp
+       add     #-(4+4+DL_DATA_SIZE), r15
+       mov     r15, r5                 // dl_data
        bsr     1f
         nop
 1:
 .L_offbase:
        sts     pr, r0
        mov.l   .L_dynamic, r6
-       add     r0, r6
-       mov      r14, r15
-       mov     r15, r14
+       add     r0, r6                  // DYNAMIC
        mov.l   .L_boot_bind, r0
-       bsrf    r0
+       bsrf    r0                      // boot_bind(sp, dl_data, DYNAMIC)
         nop
 .L_call_boot_bind:
        mov     r12, r4
-       add     #4, r4
-       mov.l   @r12, r5                //loads argc
+       add     #4, r4                  // argv
+       mov.l   @r12, r5
        add     #2, r5
        shll2   r5
-       add     r12, r5                 // calc argv 
-
-       mov     r13, r7
+       add     r12, r5                 // envp 
+       mov     r15, r7                 // dl_data
        mov     r7, r6
-       mov.l   .L_loff, r0
-       add     r0, r6
-       mov.l   @r6, r6
+       add     #(7*4), r6
+       mov.l   @r6, r6                 // dl_data[AUX_base] == loff
 
        mov.l   .L_boot, r0
-       bsrf    r0
+       bsrf    r0                      // _dl_boot(argv, envp, loff, dl_data)
         nop
 .L_call_boot:
-
        mov     r12, r15
-       lds     r11, pr
-       mov.l   @r15, r4
+       mov.l   @r15, r4                // argc
        mov     r15, r5
-       add     #4, r5
+       add     #4, r5                  // argv
 
        mov     r4, r6
        add     #1, r6
        shll2   r6
-       add     r5, r6                  // calc envp
+       add     r5, r6                  // envp
 
        mov     r0, r12
        mova    .L_GOT, r0
@@ -99,12 +85,8 @@ ENTRY(_dl_start)
        .long _dl_boot_bind-.L_call_boot_bind
 .L_boot:
        .long _dl_boot-.L_call_boot
-.L_datasize:
-       .long 4+4+DL_DATA_SIZE
 .L_dynamic:
        .long _DYNAMIC-.L_offbase
-.L_loff:
-       .long 7*4
 .L_GOT:
        .long _GLOBAL_OFFSET_TABLE_
 .L_dl_dtors: