github.com/prattmic/llgo-embedded@v0.0.0-20150820070356-41cfecea0e1e/third_party/gofrontend/libffi/src/powerpc/sysv.S (about)

     1  /* -----------------------------------------------------------------------
     2     sysv.S - Copyright (c) 1998 Geoffrey Keating
     3     Copyright (C) 2007 Free Software Foundation, Inc
     4  
     5     PowerPC Assembly glue.
     6  
     7     Permission is hereby granted, free of charge, to any person obtaining
     8     a copy of this software and associated documentation files (the
     9     ``Software''), to deal in the Software without restriction, including
    10     without limitation the rights to use, copy, modify, merge, publish,
    11     distribute, sublicense, and/or sell copies of the Software, and to
    12     permit persons to whom the Software is furnished to do so, subject to
    13     the following conditions:
    14  
    15     The above copyright notice and this permission notice shall be included
    16     in all copies or substantial portions of the Software.
    17  
    18     THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND,
    19     EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
    20     MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
    21     NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
    22     HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
    23     WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    24     OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
    25     DEALINGS IN THE SOFTWARE.
    26     ----------------------------------------------------------------------- */
    27  
    28  #define LIBFFI_ASM
    29  #include <fficonfig.h>
    30  #include <ffi.h>
    31  #include <powerpc/asm.h>
    32  
    33  #ifndef POWERPC64
    34  FFI_HIDDEN(ffi_call_SYSV)
    35  ENTRY(ffi_call_SYSV)
    36  	.cfi_startproc
    37  	/* Save the old stack pointer as AP.  */
    38  	mr	%r10,%r1
    39  	.cfi_def_cfa_register 10
    40  
    41  	/* Allocate the stack space we need.  */
    42  	stwux	%r1,%r1,%r8
    43  	/* Save registers we use.  */
    44  	mflr	%r9
    45  	stw	%r28,-16(%r10)
    46  	stw	%r29,-12(%r10)
    47  	stw	%r30, -8(%r10)
    48  	stw	%r31, -4(%r10)
    49  	stw	%r9,   4(%r10)
    50  	.cfi_offset 65, 4
    51  	.cfi_offset 31, -4
    52  	.cfi_offset 30, -8
    53  	.cfi_offset 29, -12
    54  	.cfi_offset 28, -16
    55  
    56  	/* Save arguments over call...  */
    57  	stw	%r7,   -20(%r10)	/* closure, */
    58  	mr	%r31,%r6		/* flags, */
    59  	mr	%r30,%r5		/* rvalue, */
    60  	mr	%r29,%r4		/* function address, */
    61  	mr	%r28,%r10		/* our AP. */
    62  	.cfi_def_cfa_register 28
    63  
    64  	/* Call ffi_prep_args_SYSV.  */
    65  	mr	%r4,%r1
    66  	bl	ffi_prep_args_SYSV@local
    67  
    68  	/* Now do the call.  */
    69  	/* Set up cr1 with bits 4-7 of the flags.  */
    70  	mtcrf	0x40,%r31
    71  	/* Get the address to call into CTR.  */
    72  	mtctr	%r29
    73  	/* Load all those argument registers.  */
    74  	lwz	%r3,-24-(8*4)(%r28)
    75  	lwz	%r4,-24-(7*4)(%r28)
    76  	lwz	%r5,-24-(6*4)(%r28)
    77  	lwz	%r6,-24-(5*4)(%r28)
    78  	bf-	5,1f
    79  	nop
    80  	lwz	%r7,-24-(4*4)(%r28)
    81  	lwz	%r8,-24-(3*4)(%r28)
    82  	lwz	%r9,-24-(2*4)(%r28)
    83  	lwz	%r10,-24-(1*4)(%r28)
    84  	nop
    85  1:
    86  
    87  #ifndef __NO_FPRS__
    88  	/* Load all the FP registers.  */
    89  	bf-	6,2f
    90  	lfd	%f1,-24-(8*4)-(8*8)(%r28)
    91  	lfd	%f2,-24-(8*4)-(7*8)(%r28)
    92  	lfd	%f3,-24-(8*4)-(6*8)(%r28)
    93  	lfd	%f4,-24-(8*4)-(5*8)(%r28)
    94  	nop
    95  	lfd	%f5,-24-(8*4)-(4*8)(%r28)
    96  	lfd	%f6,-24-(8*4)-(3*8)(%r28)
    97  	lfd	%f7,-24-(8*4)-(2*8)(%r28)
    98  	lfd	%f8,-24-(8*4)-(1*8)(%r28)
    99  #endif
   100  2:
   101  
   102  	/* Make the call.  */
   103  	lwz	%r11, -20(%r28)
   104  	bctrl
   105  
   106  	/* Now, deal with the return value.  */
   107  	mtcrf	0x01,%r31 /* cr7  */
   108  	bt-	31,L(small_struct_return_value)
   109  	bt-	30,L(done_return_value)
   110  #ifndef __NO_FPRS__
   111  	bt-	29,L(fp_return_value)
   112  #endif
   113  	stw	%r3,0(%r30)
   114  	bf+	28,L(done_return_value)
   115  	stw	%r4,4(%r30)
   116  	mtcrf	0x02,%r31 /* cr6  */
   117  	bf	27,L(done_return_value)
   118  	stw     %r5,8(%r30)
   119  	stw	%r6,12(%r30)
   120  	/* Fall through...  */
   121  
   122  L(done_return_value):
   123  	/* Restore the registers we used and return.  */
   124  	lwz	%r9,   4(%r28)
   125  	lwz	%r31, -4(%r28)
   126  	mtlr	%r9
   127  	lwz	%r30, -8(%r28)
   128  	lwz	%r29,-12(%r28)
   129  	lwz	%r28,-16(%r28)
   130  	.cfi_remember_state
   131  	/* At this point we don't have a cfa register.  Say all our
   132  	   saved regs have been restored.  */
   133  	.cfi_same_value 65
   134  	.cfi_same_value 31
   135  	.cfi_same_value 30
   136  	.cfi_same_value 29
   137  	.cfi_same_value 28
   138  	/* Hopefully this works..  */
   139  	.cfi_def_cfa_register 1
   140  	.cfi_offset 1, 0
   141  	lwz	%r1,0(%r1)
   142  	.cfi_same_value 1
   143  	blr
   144  
   145  #ifndef __NO_FPRS__
   146  L(fp_return_value):
   147  	.cfi_restore_state
   148  	bf	28,L(float_return_value)
   149  	stfd	%f1,0(%r30)
   150  	mtcrf   0x02,%r31 /* cr6  */
   151  	bf	27,L(done_return_value)
   152  	stfd	%f2,8(%r30)
   153  	b	L(done_return_value)
   154  L(float_return_value):
   155  	stfs	%f1,0(%r30)
   156  	b	L(done_return_value)
   157  #endif
   158  
   159  L(small_struct_return_value):
   160  	/*
   161  	 * The C code always allocates a properly-aligned 8-byte bounce
   162  	 * buffer to make this assembly code very simple.  Just write out
   163  	 * r3 and r4 to the buffer to allow the C code to handle the rest.
   164  	 */
   165  	stw %r3, 0(%r30)
   166  	stw %r4, 4(%r30)
   167  	b L(done_return_value)
   168  	.cfi_endproc
   169  
   170  END(ffi_call_SYSV)
   171  
   172  #if defined __ELF__ && defined __linux__
   173  	.section	.note.GNU-stack,"",@progbits
   174  #endif
   175  #endif