From: Felix Fietkau <nbd@openwrt.org>
Date: Wed, 8 Jul 2015 13:56:37 +0200
Subject: [PATCH] Add PowerPC soft-float support

Some PowerPC CPUs (e.g. Freescale MPC85xx) have a completely different
instruction set for floating point operations (SPE).
Executing regular PowerPC floating point instructions results in
"Illegal instruction" errors.

Make it possible to run these devices in soft-float mode.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
---
 create mode 100644 src/fenv/powerpc/fenv-sf.c

--- a/arch/powerpc/bits/fenv.h
+++ b/arch/powerpc/bits/fenv.h
@@ -1,3 +1,7 @@
+#ifdef _SOFT_FLOAT
+#define FE_ALL_EXCEPT 0
+#define FE_TONEAREST  0
+#else
 #define FE_TONEAREST	0
 #define FE_TOWARDZERO	1
 #define FE_UPWARD	2
@@ -24,6 +28,7 @@
 
 #define FE_ALL_INVALID		0x01f80700
 #endif
+#endif
 
 typedef unsigned fexcept_t;
 typedef double fenv_t;
--- a/arch/powerpc/reloc.h
+++ b/arch/powerpc/reloc.h
@@ -1,4 +1,10 @@
-#define LDSO_ARCH "powerpc"
+#ifdef _SOFT_FLOAT
+#define FP_SUFFIX "-sf"
+#else
+#define FP_SUFFIX ""
+#endif
+
+#define LDSO_ARCH "powerpc" FP_SUFFIX
 
 #define TPOFF_K (-0x7000)
 
--- a/configure
+++ b/configure
@@ -595,6 +595,10 @@ trycppif "_MIPSEL || __MIPSEL || __MIPSE
 trycppif __mips_soft_float "$t" && SUBARCH=${SUBARCH}-sf
 fi
 
+if test "$ARCH" = "powerpc" ; then
+trycppif _SOFT_FLOAT "$t" && SUBARCH=${SUBARCH}-sf
+fi
+
 test "$ARCH" = "microblaze" && trycppif __MICROBLAZEEL__ "$t" \
 && SUBARCH=${SUBARCH}el
 
--- /dev/null
+++ b/src/fenv/powerpc/fenv-sf.c
@@ -0,0 +1,3 @@
+#ifdef _SOFT_FLOAT
+#include "../fenv.c"
+#endif
--- /dev/null
+++ b/src/fenv/powerpc/fenv.S
@@ -0,0 +1,129 @@
+#ifndef _SOFT_FLOAT
+.global feclearexcept
+.type feclearexcept,@function
+feclearexcept:
+	andis. 3,3,0x3e00
+	/* if (r3 & FE_INVALID) r3 |= all_invalid_flags */
+	andis. 0,3,0x2000
+	stwu 1,-16(1)
+	beq- 0,1f
+	oris 3,3,0x01f8
+	ori  3,3,0x0700
+1:
+	/*
+	 * note: fpscr contains various fpu status and control
+	 * flags and we dont check if r3 may alter other flags
+	 * than the exception related ones
+	 * ufpscr &= ~r3
+	 */
+	mffs 0
+	stfd 0,8(1)
+	lwz 9,12(1)
+	andc 9,9,3
+	stw 9,12(1)
+	lfd 0,8(1)
+	mtfsf 255,0
+
+	/* return 0 */
+	li 3,0
+	addi 1,1,16
+	blr
+
+.global feraiseexcept
+.type feraiseexcept,@function
+feraiseexcept:
+	andis. 3,3,0x3e00
+	/* if (r3 & FE_INVALID) r3 |= software_invalid_flag */
+	andis. 0,3,0x2000
+	stwu 1,-16(1)
+	beq- 0,1f
+	ori 3,3,0x0400
+1:
+	/* fpscr |= r3 */
+	mffs 0
+	stfd 0,8(1)
+	lwz 9,12(1)
+	or 9,9,3
+	stw 9,12(1)
+	lfd 0,8(1)
+	mtfsf 255,0
+
+	/* return 0 */
+	li 3,0
+	addi 1,1,16
+	blr
+
+.global fetestexcept
+.type fetestexcept,@function
+fetestexcept:
+	andis. 3,3,0x3e00
+	/* return r3 & fpscr */
+	stwu 1,-16(1)
+	mffs 0
+	stfd 0,8(1)
+	lwz 9,12(1)
+	addi 1,1,16
+	and 3,3,9
+	blr
+
+.global fegetround
+.type fegetround,@function
+fegetround:
+	/* return fpscr & 3 */
+	stwu 1,-16(1)
+	mffs 0
+	stfd 0,8(1)
+	lwz 3,12(1)
+	addi 1,1,16
+	clrlwi 3,3,30
+	blr
+
+.global __fesetround
+.type __fesetround,@function
+__fesetround:
+	/*
+	 * note: invalid input is not checked, r3 < 4 must hold
+	 * fpscr = (fpscr & -4U) | r3
+	 */
+	stwu 1,-16(1)
+	mffs 0
+	stfd 0,8(1)
+	lwz 9,12(1)
+	clrrwi 9,9,2
+	or 9,9,3
+	stw 9,12(1)
+	lfd 0,8(1)
+	mtfsf 255,0
+
+	/* return 0 */
+	li 3,0
+	addi 1,1,16
+	blr
+
+.global fegetenv
+.type fegetenv,@function
+fegetenv:
+	/* *r3 = fpscr */
+	mffs 0
+	stfd 0,0(3)
+	/* return 0 */
+	li 3,0
+	blr
+
+.global fesetenv
+.type fesetenv,@function
+fesetenv:
+	cmpwi 3, -1
+	bne 1f
+	mflr 4
+	bl 2f
+	.zero 8
+2:	mflr 3
+	mtlr 4
+1:	/* fpscr = *r3 */
+	lfd 0,0(3)
+	mtfsf 255,0
+	/* return 0 */
+	li 3,0
+	blr
+#endif
--- a/src/fenv/powerpc/fenv.s
+++ /dev/null
@@ -1,123 +0,0 @@
-.global feclearexcept
-.type feclearexcept,@function
-feclearexcept:
-	andis. 3,3,0x3e00
-	# if (r3 & FE_INVALID) r3 |= all_invalid_flags
-	andis. 0,3,0x2000
-	stwu 1,-16(1)
-	beq- 0,1f
-	oris 3,3,0x01f8
-	ori  3,3,0x0700
-1:
-	# note: fpscr contains various fpu status and control
-	# flags and we dont check if r3 may alter other flags
-	# than the exception related ones
-	# fpscr &= ~r3
-	mffs 0
-	stfd 0,8(1)
-	lwz 9,12(1)
-	andc 9,9,3
-	stw 9,12(1)
-	lfd 0,8(1)
-	mtfsf 255,0
-
-	# return 0
-	li 3,0
-	addi 1,1,16
-	blr
-
-.global feraiseexcept
-.type feraiseexcept,@function
-feraiseexcept:
-	andis. 3,3,0x3e00
-	# if (r3 & FE_INVALID) r3 |= software_invalid_flag
-	andis. 0,3,0x2000
-	stwu 1,-16(1)
-	beq- 0,1f
-	ori 3,3,0x0400
-1:
-	# fpscr |= r3
-	mffs 0
-	stfd 0,8(1)
-	lwz 9,12(1)
-	or 9,9,3
-	stw 9,12(1)
-	lfd 0,8(1)
-	mtfsf 255,0
-
-	# return 0
-	li 3,0
-	addi 1,1,16
-	blr
-
-.global fetestexcept
-.type fetestexcept,@function
-fetestexcept:
-	andis. 3,3,0x3e00
-	# return r3 & fpscr
-	stwu 1,-16(1)
-	mffs 0
-	stfd 0,8(1)
-	lwz 9,12(1)
-	addi 1,1,16
-	and 3,3,9
-	blr
-
-.global fegetround
-.type fegetround,@function
-fegetround:
-	# return fpscr & 3
-	stwu 1,-16(1)
-	mffs 0
-	stfd 0,8(1)
-	lwz 3,12(1)
-	addi 1,1,16
-	clrlwi 3,3,30
-	blr
-
-.global __fesetround
-.type __fesetround,@function
-__fesetround:
-	# note: invalid input is not checked, r3 < 4 must hold
-	# fpscr = (fpscr & -4U) | r3
-	stwu 1,-16(1)
-	mffs 0
-	stfd 0,8(1)
-	lwz 9,12(1)
-	clrrwi 9,9,2
-	or 9,9,3
-	stw 9,12(1)
-	lfd 0,8(1)
-	mtfsf 255,0
-
-	# return 0
-	li 3,0
-	addi 1,1,16
-	blr
-
-.global fegetenv
-.type fegetenv,@function
-fegetenv:
-	# *r3 = fpscr
-	mffs 0
-	stfd 0,0(3)
-	# return 0
-	li 3,0
-	blr
-
-.global fesetenv
-.type fesetenv,@function
-fesetenv:
-	cmpwi 3, -1
-	bne 1f
-	mflr 4
-	bl 2f
-	.zero 8
-2:	mflr 3
-	mtlr 4
-1:	# fpscr = *r3
-	lfd 0,0(3)
-	mtfsf 255,0
-	# return 0
-	li 3,0
-	blr
--- /dev/null
+++ b/src/setjmp/powerpc/longjmp.S
@@ -0,0 +1,69 @@
+	.global _longjmp
+	.global longjmp
+	.type   _longjmp,@function
+	.type   longjmp,@function
+_longjmp:
+longjmp:
+	/*
+	 * void longjmp(jmp_buf env, int val);
+	 * put val into return register and restore the env saved in setjmp
+	 * if val(r4) is 0, put 1 there.
+	 */
+	/* 0) move old return address into r0 */
+	lwz 0, 0(3)
+	/* 1) put it into link reg */
+	mtlr 0
+	/* 2 ) restore stack ptr */
+	lwz 1, 4(3)
+	/* 3) restore control reg */
+	lwz 0, 8(3)
+	mtcr 0
+	/* 4) restore r14-r31 */
+	lwz 14, 12(3)
+	lwz 15, 16(3)
+	lwz 16, 20(3)
+	lwz 17, 24(3)
+	lwz 18, 28(3)
+	lwz 19, 32(3)
+	lwz 20, 36(3)
+	lwz 21, 40(3)
+	lwz 22, 44(3)
+	lwz 23, 48(3)
+	lwz 24, 52(3)
+	lwz 25, 56(3)
+	lwz 26, 60(3)
+	lwz 27, 64(3)
+	lwz 28, 68(3)
+	lwz 29, 72(3)
+	lwz 30, 76(3)
+	lwz 31, 80(3)
+#ifndef _SOFT_FLOAT
+	lfd 14,88(3)
+	lfd 15,96(3)
+	lfd 16,104(3)
+	lfd 17,112(3)
+	lfd 18,120(3)
+	lfd 19,128(3)
+	lfd 20,136(3)
+	lfd 21,144(3)
+	lfd 22,152(3)
+	lfd 23,160(3)
+	lfd 24,168(3)
+	lfd 25,176(3)
+	lfd 26,184(3)
+	lfd 27,192(3)
+	lfd 28,200(3)
+	lfd 29,208(3)
+	lfd 30,216(3)
+	lfd 31,224(3)
+#endif
+	/* 5) put val into return reg r3 */
+	mr 3, 4
+
+	/* 6) check if return value is 0, make it 1 in that case */
+	cmpwi cr7, 4, 0
+	bne cr7, 1f
+	li 3, 1
+1:
+	blr
+
--- a/src/setjmp/powerpc/longjmp.s
+++ /dev/null
@@ -1,65 +0,0 @@
-	.global _longjmp
-	.global longjmp
-	.type   _longjmp,@function
-	.type   longjmp,@function
-_longjmp:
-longjmp:
-# void longjmp(jmp_buf env, int val);
-# put val into return register and restore the env saved in setjmp
-# if val(r4) is 0, put 1 there.
-	# 0) move old return address into r0
-	lwz 0, 0(3)
-	# 1) put it into link reg
-	mtlr 0
-	#2 ) restore stack ptr
-	lwz 1, 4(3)
-	#3) restore control reg
-	lwz 0, 8(3)
-	mtcr 0
-	#4) restore r14-r31
-	lwz 14, 12(3)
-	lwz 15, 16(3)
-	lwz 16, 20(3)
-	lwz 17, 24(3)
-	lwz 18, 28(3)
-	lwz 19, 32(3)
-	lwz 20, 36(3)
-	lwz 21, 40(3)
-	lwz 22, 44(3)
-	lwz 23, 48(3)
-	lwz 24, 52(3)
-	lwz 25, 56(3)
-	lwz 26, 60(3)
-	lwz 27, 64(3)
-	lwz 28, 68(3)
-	lwz 29, 72(3)
-	lwz 30, 76(3)
-	lwz 31, 80(3)
-	lfd 14,88(3)
-	lfd 15,96(3)
-	lfd 16,104(3)
-	lfd 17,112(3)
-	lfd 18,120(3)
-	lfd 19,128(3)
-	lfd 20,136(3)
-	lfd 21,144(3)
-	lfd 22,152(3)
-	lfd 23,160(3)
-	lfd 24,168(3)
-	lfd 25,176(3)
-	lfd 26,184(3)
-	lfd 27,192(3)
-	lfd 28,200(3)
-	lfd 29,208(3)
-	lfd 30,216(3)
-	lfd 31,224(3)
-	#5) put val into return reg r3
-	mr 3, 4
-
-	#6) check if return value is 0, make it 1 in that case
-	cmpwi cr7, 4, 0
-	bne cr7, 1f
-	li 3, 1
-1:
-	blr
-
--- /dev/null
+++ b/src/setjmp/powerpc/setjmp.S
@@ -0,0 +1,63 @@
+	.global ___setjmp
+	.hidden ___setjmp
+	.global __setjmp
+	.global _setjmp
+	.global setjmp
+	.type   __setjmp,@function
+	.type   _setjmp,@function
+	.type   setjmp,@function
+___setjmp:
+__setjmp:
+_setjmp:
+setjmp:
+	/* 0) store IP int 0, then into the jmpbuf pointed to by r3 (first arg) */
+	mflr 0
+	stw 0, 0(3)
+	/* 1) store reg1 (SP) */
+	stw 1, 4(3)
+	/* 2) store cr */
+	mfcr 0
+	stw 0, 8(3)
+	/* 3) store r14-31 */
+	stw 14, 12(3)
+	stw 15, 16(3)
+	stw 16, 20(3)
+	stw 17, 24(3)
+	stw 18, 28(3)
+	stw 19, 32(3)
+	stw 20, 36(3)
+	stw 21, 40(3)
+	stw 22, 44(3)
+	stw 23, 48(3)
+	stw 24, 52(3)
+	stw 25, 56(3)
+	stw 26, 60(3)
+	stw 27, 64(3)
+	stw 28, 68(3)
+	stw 29, 72(3)
+	stw 30, 76(3)
+	stw 31, 80(3)
+#ifndef _SOFT_FLOAT
+	stfd 14,88(3)
+	stfd 15,96(3)
+	stfd 16,104(3)
+	stfd 17,112(3)
+	stfd 18,120(3)
+	stfd 19,128(3)
+	stfd 20,136(3)
+	stfd 21,144(3)
+	stfd 22,152(3)
+	stfd 23,160(3)
+	stfd 24,168(3)
+	stfd 25,176(3)
+	stfd 26,184(3)
+	stfd 27,192(3)
+	stfd 28,200(3)
+	stfd 29,208(3)
+	stfd 30,216(3)
+	stfd 31,224(3)
+#endif
+	/* 4) set return value to 0 */
+	li 3, 0
+	/* 5) return */
+	blr
--- a/src/setjmp/powerpc/setjmp.s
+++ /dev/null
@@ -1,61 +0,0 @@
-	.global ___setjmp
-	.hidden ___setjmp
-	.global __setjmp
-	.global _setjmp
-	.global setjmp
-	.type   __setjmp,@function
-	.type   _setjmp,@function
-	.type   setjmp,@function
-___setjmp:
-__setjmp:
-_setjmp:
-setjmp:
-	# 0) store IP int 0, then into the jmpbuf pointed to by r3 (first arg)
-	mflr 0
-	stw 0, 0(3)
-	# 1) store reg1 (SP)
-	stw 1, 4(3)
-	# 2) store cr
-	mfcr 0
-	stw 0, 8(3)
-	# 3) store r14-31
-	stw 14, 12(3)
-	stw 15, 16(3)
-	stw 16, 20(3)
-	stw 17, 24(3)
-	stw 18, 28(3)
-	stw 19, 32(3)
-	stw 20, 36(3)
-	stw 21, 40(3)
-	stw 22, 44(3)
-	stw 23, 48(3)
-	stw 24, 52(3)
-	stw 25, 56(3)
-	stw 26, 60(3)
-	stw 27, 64(3)
-	stw 28, 68(3)
-	stw 29, 72(3)
-	stw 30, 76(3)
-	stw 31, 80(3)
-	stfd 14,88(3)
-	stfd 15,96(3)
-	stfd 16,104(3)
-	stfd 17,112(3)
-	stfd 18,120(3)
-	stfd 19,128(3)
-	stfd 20,136(3)
-	stfd 21,144(3)
-	stfd 22,152(3)
-	stfd 23,160(3)
-	stfd 24,168(3)
-	stfd 25,176(3)
-	stfd 26,184(3)
-	stfd 27,192(3)
-	stfd 28,200(3)
-	stfd 29,208(3)
-	stfd 30,216(3)
-	stfd 31,224(3)
-	# 4) set return value to 0
-	li 3, 0
-	# 5) return
-	blr