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-rw-r--r--ports/sysdeps/tile/dl-trampoline.S193
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diff --git a/ports/sysdeps/tile/dl-trampoline.S b/ports/sysdeps/tile/dl-trampoline.S
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+/* Copyright (C) 2011 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sysdep.h>
+#include <arch/abi.h>
+
+/* This function is called via the PLT header, which is called
+   from an individual PLT entry.
+
+   At this point we have several values passed in:
+
+   lr:  return address to original user code
+   r28: the tpnt value to pass to _dl_runtime_resolver
+   r29: the PLT index of the invoked jump table entry.
+
+   We set up a frame entry that looks like this (in int_reg_t units):
+
+   +57: r25 return values from function...
+   +56: r24
+   [...]
+   +33: r1
+   +32: r0
+   +31: PLT index
+   +30: tpnt
+   +29: stackframe
+   +28: caller lr
+   +27: r25 arguments to function...
+   +26: r24
+   [...]
+   +3:  r1
+   +2:  r0
+   +1:  standard ABI slot (sp)
+   +0:  standard ABI slot (callee lr)
+
+   The entries from "stackframe" up are only used in _dl_profile_resolve.
+   We save and restore r0 through r25, rather than the strictly
+   architected r0 through r9, to support unusual calling conventions;
+   for example, __tls_get_addr takes r0 and returns r0, but promises
+   not to clobber r1 through r24 to support its usual fast path.  */
+
+#define FRAME_SP		(1 * REGSIZE)
+#define FRAME_REGS		(2 * REGSIZE)
+#define FRAME_LR		(28 * REGSIZE)  /* Must follow FRAME_REGS */
+#define FRAME_STACKFRAME	(29 * REGSIZE)
+#define FRAME_TPNT		(30 * REGSIZE)
+#define FRAME_INDEX		(31 * REGSIZE)
+#define FRAME_RETVAL		(32 * REGSIZE)
+
+#define FRAME_SIZE_SMALL	(30 * REGSIZE)
+#define FRAME_SIZE_LARGE	(58 * REGSIZE)
+
+#define FOR_EACH_REG(f) \
+	f(r0);  f(r1);  f(r2);  f(r3);  \
+	f(r4);  f(r5);  f(r6);  f(r7);  \
+	f(r8);  f(r9);  f(r10); f(r11); \
+	f(r12); f(r13); f(r14); f(r15); \
+	f(r16); f(r17); f(r18); f(r19); \
+	f(r20); f(r21); f(r22); f(r23); \
+	f(r24); f(r25)
+
+#define SAVE(REG) { ST r27, REG; ADDI_PTR r27, r27, REGSIZE }
+#define RESTORE(REG) { LD REG, r27; ADDI_PTR r27, r27, REGSIZE }
+
+	.macro dl_resolve, name, profile, framesize
+.text
+.global \name
+.hidden \name
+/* Note that cpp expands ENTRY(\name) incorrectly. */
+.type \name,@function
+.align 8
+\name:
+	cfi_startproc
+	{
+	 ST sp, lr
+	 move r26, sp
+	}
+	{
+	 ADDLI_PTR sp, sp, -\framesize
+	 ADDLI_PTR r27, sp, FRAME_SP - \framesize
+	}
+	cfi_def_cfa_offset (\framesize)
+	{
+	 ST r27, r26
+	 ADDI_PTR r27, r27, FRAME_REGS - FRAME_SP
+	}
+	FOR_EACH_REG(SAVE)
+	{
+	 ST r27, lr
+	 ADDLI_PTR r27, sp, FRAME_TPNT
+	}
+	cfi_offset (lr, FRAME_LR - \framesize)
+	.if \profile
+	{
+	 move r0, r28  /* tpnt value */
+	 ST r27, r28
+	 ADDI_PTR r27, r27, FRAME_INDEX - FRAME_TPNT
+	}
+	{
+	 move r1, r29  /* PLT index */
+	 ST r27, r29
+	}
+	{
+	 move r2, lr  /* retaddr */
+	 ADDI_PTR r3, sp, FRAME_REGS  /* La_tile_regs pointer */
+	}
+	{
+	 ADDLI_PTR r4, sp, FRAME_STACKFRAME  /* framesize pointer */
+	 jal _dl_profile_fixup
+	}
+	ADDLI_PTR r28, sp, FRAME_STACKFRAME
+	LD_PTR r28, r28
+	BGTZ r28, 1f
+	.else
+	{
+	 move r0, r28  /* tpnt value 1 */
+	 move r1, r29  /* PLT index 2 */
+	}
+	jal _dl_fixup
+	.endif
+	{
+	 /* Copy aside the return value so we can restore r0 below. */
+	 move r29, r0
+	 /* Set up r27 to let us start restoring registers. */
+	 ADDLI_PTR r27, sp, FRAME_REGS
+	}
+	FOR_EACH_REG(RESTORE)
+	.if \profile
+	ADDLI_PTR r28, sp, FRAME_STACKFRAME
+	LD r28, r28
+	BGTZ r28, 1f
+	.endif
+	{
+	 /* Restore original user return address. */
+	 LD lr, r27
+	 /* Pop off our stack frame. */
+	 ADDLI_PTR sp, sp, \framesize
+	}
+	cfi_def_cfa_offset (0)
+	jr r29  /* Transfer control to freshly loaded code. */
+	jrp lr  /* Keep backtracer happy. */
+
+	.if \profile
+1:	jalr r29   /* Call resolved function. */
+	{
+	 ADDLI_PTR r28, sp, FRAME_TPNT
+	 ADDLI_PTR r27, sp, FRAME_RETVAL
+	}
+	FOR_EACH_REG(SAVE)
+	{
+	 LD r0, r28
+	 ADDI_PTR r28, r28, FRAME_INDEX - FRAME_TPNT
+	}
+        {
+	 LD r1, r28
+	 ADDLI_PTR r2, sp, FRAME_REGS
+	}
+	{
+	 ADDLI_PTR r3, sp, FRAME_RETVAL
+	 jal _dl_call_pltexit
+	}
+	{
+	 ADDLI_PTR lr, sp, FRAME_LR
+	 ADDLI_PTR r27, sp, FRAME_RETVAL
+        }
+	FOR_EACH_REG(RESTORE)
+	{
+	 LD lr, lr
+	 ADDLI_PTR sp, sp, \framesize
+	}
+	jrp lr
+	.endif
+END (\name)
+	.endm
+
+	dl_resolve _dl_runtime_resolve, 0, FRAME_SIZE_SMALL
+#ifndef PROF
+	dl_resolve _dl_runtime_profile, 1, FRAME_SIZE_LARGE
+#endif