From: Mark Wooding <mdw@distorted.org.uk>
Date: Thu, 26 May 2016 08:26:09 +0000 (+0100)
Subject: base/asm-common.h, *.S: Introduce `AUXFN'/`ENDAUXFN'; abolish `gotaux'.
X-Git-Tag: 2.3.0~49
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/catacomb/commitdiff_plain/8ae4c946c49862151bf7fd6ae65b116ec62be606

base/asm-common.h, *.S: Introduce `AUXFN'/`ENDAUXFN'; abolish `gotaux'.

This change introduces a new macro pair `AUXFN' and `ENDAUXFN' which are
mostly useful in other macros.  They bracket an auxiliary function
definition which will be put somewhere convenient (at the end of the
text section), and defined exactly once.

This is exactly what we need to make the `_where_am_i.GOTREG' macros
automatically in `ldgot', so use this and abolish `gotaux' from the
codebase.
---

diff --git a/base/asm-common.h b/base/asm-common.h
index 8ab0bc0a..0b5f2238 100644
--- a/base/asm-common.h
+++ b/base/asm-common.h
@@ -51,6 +51,19 @@ F(name):								\
 	ENDFUNC_HOOK(name);						\
 	_LTORG
 
+// Make a helper function, if necessary.
+#define AUXFN(name)							\
+  .ifndef .L$_auxfn_def.name;						\
+	.text 7128;							\
+	.macro _ENDAUXFN; _ENDAUXFN_TAIL(name); .endm;			\
+	FUNC_PREHOOK(name);						\
+name:
+#define _ENDAUXFN_TAIL(name)						\
+	.purgem _ENDAUXFN;						\
+	.text .L$_subsec;						\
+	.L$_auxfn_def.name = 1
+#define ENDAUXFN _ENDAUXFN; .endif
+
 ///--------------------------------------------------------------------------
 /// ELF-specific hacking.
 
@@ -109,18 +122,12 @@ F(name):								\
 // Maybe load GOT address into GOT.
 .macro	ldgot got=GOTREG
 #if WANT_PIC && CPUFAM_X86
-	call	_where_am_i.\got
-	add	\got, offset _GLOBAL_OFFSET_TABLE_
-#endif
-.endm
-
-// Maybe build a helper subroutine for `ldgot GOT'.
-.macro	gotaux got=GOTREG
-#if WANT_PIC && CPUFAM_X86
-	.align	16
-_where_am_i.\got :
+  AUXFN(_ldgot.\got)
 	mov	\got, [esp]
 	ret
+  ENDAUXFN
+	call	_ldgot.\got
+	add	\got, offset _GLOBAL_OFFSET_TABLE_
 #endif
 .endm
 
diff --git a/symm/rijndael-x86ish-aesni.S b/symm/rijndael-x86ish-aesni.S
index 5194c17d..12d4267f 100644
--- a/symm/rijndael-x86ish-aesni.S
+++ b/symm/rijndael-x86ish-aesni.S
@@ -546,8 +546,6 @@ bogus:	callext	F(abort)
 0:	hlt
 	jmp	0b
 
-	gotaux	ecx
-
 ///--------------------------------------------------------------------------
 /// Data tables.