Re: [RFC 2/3] Move trampolines to common header.

[OndÅej BÃlka <neleai at seznam dot cz>]

On Sat, Oct 19, 2013 at 10:24:12AM +0200, OndÅej BÃlka wrote:
> Hi, I returned to storing floating point registers. A first step is
> refactor code so it can be factored out in second patch and sse saving
> logic in third patch. A code now is inconsistent in several ways:
> 
This is second patch. There may be some modifications depending on
feedback from first patch.

Comments?

	* sysdeps/x86_64/dl-trampoline-real.h: New file.
	* sysdeps/x86_64/dl-tlsdesc.S: Factor common code out.
	* sysdeps/x86_64/dl-trampoline.S: Likewise.


diff --git a/sysdeps/x86_64/dl-tlsdesc.S b/sysdeps/x86_64/dl-tlsdesc.S
index c439c7e..f945a63 100644
--- a/sysdeps/x86_64/dl-tlsdesc.S
+++ b/sysdeps/x86_64/dl-tlsdesc.S
@@ -115,22 +115,17 @@ _dl_tlsdesc_dynamic:
 .Lslow:
 	/* Besides rdi and rsi, saved above, save rdx, rcx, r8, r9,
 	   Also, align the stack, that's off by 8 bytes.	*/
-	subq	$72, %rsp
-	cfi_adjust_cfa_offset (72)
-	movq	%rdx, 8(%rsp)
-	movq	%rcx, 16(%rsp)
-	movq	%r8, 24(%rsp)
-	movq	%r9, 32(%rsp)
-
-	movq %r11, %rdi
-	call	__tls_get_addr@PLT
-
-	movq	8(%rsp), %rdx
-	movq	16(%rsp), %rcx
-	movq	24(%rsp), %r8
-	movq	32(%rsp), %r9
-	addq	$72, %rsp
-	cfi_adjust_cfa_offset (-72)
+
+
+#define PREFIX dynamic
+#define MIDDLE \
+	movq	%r11, %rdi; \
+	call	__tls_get_addr@PLT; \
+	movq	%rax, %r11
+
+#include "dl-trampoline-real.h"
+
+	movq	%r11, %rax
 	jmp	.Lret
 	cfi_endproc
 	.size	_dl_tlsdesc_dynamic, .-_dl_tlsdesc_dynamic
@@ -156,32 +151,18 @@ _dl_tlsdesc_dynamic:
 	.align 16
 	/* The PLT entry will have pushed the link_map pointer.  */
 _dl_tlsdesc_resolve_rela:
-	cfi_adjust_cfa_offset (8)
 	/* Save all call-clobbered registers.  */
 	movq (%rsp), %r11
-	subq	$72, %rsp
-	cfi_adjust_cfa_offset (72)
-	movq	%rax, (%rsp)
-	movq	%rdi, 8(%rsp)
-	movq	%rsi, 16(%rsp)
-	movq	%r8, 24(%rsp)
-	movq	%r9, 32(%rsp)
-	movq	%rdx, 56(%rsp)
-	movq	%rcx, 64(%rsp)
-
-	movq	%rax, %rdi	/* Pass tlsdesc* in %rdi.  */
-  movq  %r11, %rsi /* Pass link_map* in %rsi.  */
-	call	_dl_tlsdesc_resolve_rela_fixup
-
-	movq	(%rsp), %rax
-	movq	8(%rsp), %rdi
-	movq	16(%rsp), %rsi
-	movq	24(%rsp), %r8
-	movq	32(%rsp), %r9
-	movq	56(%rsp), %rdx
-	movq	64(%rsp), %rcx
-	addq	$80, %rsp
-	cfi_adjust_cfa_offset (-80)
+	addq $8, %rsp
+
+#define PREFIX rela
+#define MIDDLE \
+	movq	%rax, %rdi ;	/* Pass tlsdesc* in %rdi.  */ \
+	movq	%r11, %rsi ;	/* Pass link_map* in %rsi.  */ \
+	call	_dl_tlsdesc_resolve_rela_fixup \
+
+#include "dl-trampoline-real.h"
+
 	jmp	*(%rax)
 	cfi_endproc
 	.size	_dl_tlsdesc_resolve_rela, .-_dl_tlsdesc_resolve_rela
@@ -203,31 +184,14 @@ _dl_tlsdesc_resolve_rela:
 	cfi_startproc
 	.align 16
 _dl_tlsdesc_resolve_hold:
-	/* Save all call-clobbered registers.  */
-	subq	$72, %rsp
-	cfi_adjust_cfa_offset (72)
-	movq	%rax, (%rsp)
-	movq	%rdi, 8(%rsp)
-	movq	%rsi, 16(%rsp)
-	/* Pass _dl_tlsdesc_resolve_hold's address in %rsi.  */
-	movq	%r8, 24(%rsp)
-	movq	%r9, 32(%rsp)
-	movq	%rdx, 56(%rsp)
-	movq	%rcx, 64(%rsp)
-
-	movq	%rax, %rdi	/* Pass tlsdesc* in %rdi.  */
-	leaq	. - _dl_tlsdesc_resolve_hold(%rip), %rsi
-	call	_dl_tlsdesc_resolve_hold_fixup
-
-	movq	(%rsp), %rax
-	movq	8(%rsp), %rdi
-	movq	16(%rsp), %rsi
-	movq	24(%rsp), %r8
-	movq	32(%rsp), %r9
-	movq	56(%rsp), %rdx
-	movq	64(%rsp), %rcx
-	addq	$72, %rsp
-	cfi_adjust_cfa_offset (-72)
+
+#define PREFIX hold
+#define MIDDLE \
+	movq	%rax, %rdi;	/* Pass tlsdesc* in %rdi.  */ \
+	leaq	. - _dl_tlsdesc_resolve_hold(%rip), %rsi; \
+	call	_dl_tlsdesc_resolve_hold_fixup; 
+#include "dl-trampoline-real.h"
+
 	jmp	*(%rax)
 	cfi_endproc
 	.size	_dl_tlsdesc_resolve_hold, .-_dl_tlsdesc_resolve_hold
diff --git a/sysdeps/x86_64/dl-trampoline.S b/sysdeps/x86_64/dl-trampoline.S
index 4212145..ae30aca 100644
--- a/sysdeps/x86_64/dl-trampoline.S
+++ b/sysdeps/x86_64/dl-trampoline.S
@@ -32,31 +32,18 @@
 _dl_runtime_resolve:
 	movq (%rsp), %r10
 	movq 8(%rsp), %r11
-	cfi_adjust_cfa_offset(16) # Incorporate PLT
-	subq $56,%rsp
-	cfi_adjust_cfa_offset(56)
-	movq %rax,(%rsp)	# Preserve registers otherwise clobbered.
-	movq %rcx, 8(%rsp)
-	movq %rdx, 16(%rsp)
-	movq %rsi, 24(%rsp)
-	movq %rdi, 32(%rsp)
-	movq %r8, 40(%rsp)
-	movq %r9, 48(%rsp)
-
-	movq %r11, %rsi	# Copy args pushed by PLT in register.
-	movq %r10, %rdi	# %rdi: link_map, %rsi: reloc_index
-	call _dl_fixup		# Call resolver.
-	movq %rax, %r11		# Save return value
-
-	movq 48(%rsp), %r9	# Get register content back.
-	movq 40(%rsp), %r8
-	movq 32(%rsp), %rdi
-	movq 24(%rsp), %rsi
-	movq 16(%rsp), %rdx
-	movq 8(%rsp), %rcx
-	movq (%rsp), %rax
-	addq $72, %rsp		# Adjust stack(PLT did 2 pushes)
-	cfi_adjust_cfa_offset(-72)
+
+	addq $16, %rsp
+
+	#define PREFIX DL
+	#define MIDDLE \
+	movq %r11, %rsi;	/* Copy args pushed by PLT in register.  */ \
+	movq %r10, %rdi;	/* %rdi: link_map, %rsi: reloc_index */ \
+	call _dl_fixup;		/* Call resolver.  */ \
+	movq %rax, %r11;	/* Save return value.  */
+
+#include "dl-trampoline-real.h"
+
 	jmp *%r11		# Jump to function address.
 	cfi_endproc
 	.size _dl_runtime_resolve, .-_dl_runtime_resolve