libffi: fix MIPS softfloat build issue with current binutils

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

libs/libffi/patches/100-fix_mips_softfloat.patch

@@ -0,0 +1,79 @@
+--- a/src/mips/o32.S
++++ b/src/mips/o32.S
+@@ -82,13 +82,16 @@ sixteen:
+ 		
+ 	ADDU	$sp, 4 * FFI_SIZEOF_ARG		# adjust $sp to new args
+ 
++#ifndef __mips_soft_float
+ 	bnez	t0, pass_d			# make it quick for int
++#endif
+ 	REG_L	a0, 0*FFI_SIZEOF_ARG($sp)	# just go ahead and load the
+ 	REG_L	a1, 1*FFI_SIZEOF_ARG($sp)	# four regs.
+ 	REG_L	a2, 2*FFI_SIZEOF_ARG($sp)
+ 	REG_L	a3, 3*FFI_SIZEOF_ARG($sp)
+ 	b	call_it
+ 
++#ifndef __mips_soft_float
+ pass_d:
+ 	bne	t0, FFI_ARGS_D, pass_f
+ 	l.d	$f12, 0*FFI_SIZEOF_ARG($sp)	# load $fp regs from args
+@@ -130,6 +133,7 @@ pass_f_d:
+  #	bne	t0, FFI_ARGS_F_D, call_it
+ 	l.s	$f12, 0*FFI_SIZEOF_ARG($sp)	# load $fp regs from args
+ 	l.d	$f14, 2*FFI_SIZEOF_ARG($sp)	# passing double and float
++#endif
+ 
+ call_it:	
+ 	# Load the function pointer
+@@ -158,14 +162,23 @@ retfloat:
+ 	bne     t2, FFI_TYPE_FLOAT, retdouble
+ 	jalr	t9
+ 	REG_L	t0, SIZEOF_FRAME + 4*FFI_SIZEOF_ARG($fp)
++#ifndef __mips_soft_float
+ 	s.s	$f0, 0(t0)
++#else
++	REG_S	v0, 0(t0)
++#endif
+ 	b	epilogue
+ 
+ retdouble:	
+ 	bne	t2, FFI_TYPE_DOUBLE, noretval
+ 	jalr	t9
+ 	REG_L	t0, SIZEOF_FRAME + 4*FFI_SIZEOF_ARG($fp)
++#ifndef __mips_soft_float
+ 	s.d	$f0, 0(t0)
++#else
++	REG_S	v1, 4(t0)
++	REG_S	v0, 0(t0)
++#endif
+ 	b	epilogue
+ 	
+ noretval:	
+@@ -261,9 +274,11 @@ $LCFI7:
+ 	li	$13, 1		# FFI_O32
+ 	bne	$16, $13, 1f	# Skip fp save if FFI_O32_SOFT_FLOAT
+ 	
++#ifndef __mips_soft_float
+ 	# Store all possible float/double registers.
+ 	s.d	$f12, FA_0_0_OFF2($fp)
+ 	s.d	$f14, FA_1_0_OFF2($fp)
++#endif
+ 1:	
+ 	# Call ffi_closure_mips_inner_O32 to do the work.
+ 	la	t9, ffi_closure_mips_inner_O32
+@@ -281,6 +296,7 @@ $LCFI7:
+ 	li	$13, 1		# FFI_O32
+ 	bne	$16, $13, 1f	# Skip fp restore if FFI_O32_SOFT_FLOAT
+ 
++#ifndef __mips_soft_float
+ 	li	$9, FFI_TYPE_FLOAT
+ 	l.s	$f0, V0_OFF2($fp)
+ 	beq	$8, $9, closure_done
+@@ -288,6 +304,7 @@ $LCFI7:
+ 	li	$9, FFI_TYPE_DOUBLE
+ 	l.d	$f0, V0_OFF2($fp)
+ 	beq	$8, $9, closure_done
++#endif
+ 1:	
+ 	REG_L	$3, V1_OFF2($fp)
+ 	REG_L	$2, V0_OFF2($fp)