sh: Provide sdivsi3/udivsi3/udivdi3 for sh64, kill off libgcc linking.

This moves in the necessary libgcc bits and kills off the libgcc linking
for sh64 kernels as well.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 120 insertions, 0 deletions

diff --git a/arch/sh/lib64/udivdi3.S b/arch/sh/lib64/udivdi3.S
new file mode 100644
index 0000000..6895c02
--- /dev/null
+++ b/arch/sh/lib64/udivdi3.S
@@ -0,0 +1,120 @@
+	.section	.text..SHmedia32,"ax"
+	.align	2
+	.global	__udivdi3
+__udivdi3:
+	shlri r3,1,r4
+	nsb r4,r22
+	shlld r3,r22,r6
+	shlri r6,49,r5
+	movi 0xffffffffffffbaf1,r21 /* .l shift count 17.  */
+	sub r21,r5,r1
+	mmulfx.w r1,r1,r4
+	mshflo.w r1,r63,r1
+	sub r63,r22,r20 // r63 == 64 % 64
+	mmulfx.w r5,r4,r4
+	pta large_divisor,tr0
+	addi r20,32,r9
+	msub.w r1,r4,r1
+	madd.w r1,r1,r1
+	mmulfx.w r1,r1,r4
+	shlri r6,32,r7
+	bgt/u r9,r63,tr0 // large_divisor
+	mmulfx.w r5,r4,r4
+	shlri r2,32+14,r19
+	addi r22,-31,r0
+	msub.w r1,r4,r1
+
+	mulu.l r1,r7,r4
+	addi r1,-3,r5
+	mulu.l r5,r19,r5
+	sub r63,r4,r4 // Negate to make sure r1 ends up <= 1/r2
+	shlri r4,2,r4 /* chop off leading %0000000000000000 001.00000000000 - or, as
+	                 the case may be, %0000000000000000 000.11111111111, still */
+	muls.l r1,r4,r4 /* leaving at least one sign bit.  */
+	mulu.l r5,r3,r8
+	mshalds.l r1,r21,r1
+	shari r4,26,r4
+	shlld r8,r0,r8
+	add r1,r4,r1 // 31 bit unsigned reciprocal now in r1 (msb equiv. 0.5)
+	sub r2,r8,r2
+	/* Can do second step of 64 : 32 div now, using r1 and the rest in r2.  */
+
+	shlri r2,22,r21
+	mulu.l r21,r1,r21
+	shlld r5,r0,r8
+	addi r20,30-22,r0
+	shlrd r21,r0,r21
+	mulu.l r21,r3,r5
+	add r8,r21,r8
+	mcmpgt.l r21,r63,r21 // See Note 1
+	addi r20,30,r0
+	mshfhi.l r63,r21,r21
+	sub r2,r5,r2
+	andc r2,r21,r2
+
+	/* small divisor: need a third divide step */
+	mulu.l r2,r1,r7
+	ptabs r18,tr0
+	addi r2,1,r2
+	shlrd r7,r0,r7
+	mulu.l r7,r3,r5
+	add r8,r7,r8
+	sub r2,r3,r2
+	cmpgt r2,r5,r5
+	add r8,r5,r2
+	/* could test r3 here to check for divide by zero.  */
+	blink tr0,r63
+
+large_divisor:
+	mmulfx.w r5,r4,r4
+	shlrd r2,r9,r25
+	shlri r25,32,r8
+	msub.w r1,r4,r1
+
+	mulu.l r1,r7,r4
+	addi r1,-3,r5
+	mulu.l r5,r8,r5
+	sub r63,r4,r4 // Negate to make sure r1 ends up <= 1/r2
+	shlri r4,2,r4 /* chop off leading %0000000000000000 001.00000000000 - or, as
+	                 the case may be, %0000000000000000 000.11111111111, still */
+	muls.l r1,r4,r4 /* leaving at least one sign bit.  */
+	shlri r5,14-1,r8
+	mulu.l r8,r7,r5
+	mshalds.l r1,r21,r1
+	shari r4,26,r4
+	add r1,r4,r1 // 31 bit unsigned reciprocal now in r1 (msb equiv. 0.5)
+	sub r25,r5,r25
+	/* Can do second step of 64 : 32 div now, using r1 and the rest in r25.  */
+
+	shlri r25,22,r21
+	mulu.l r21,r1,r21
+	pta no_lo_adj,tr0
+	addi r22,32,r0
+	shlri r21,40,r21
+	mulu.l r21,r7,r5
+	add r8,r21,r8
+	shlld r2,r0,r2
+	sub r25,r5,r25
+	bgtu/u r7,r25,tr0 // no_lo_adj
+	addi r8,1,r8
+	sub r25,r7,r25
+no_lo_adj:
+	mextr4 r2,r25,r2
+
+	/* large_divisor: only needs a few adjustments.  */
+	mulu.l r8,r6,r5
+	ptabs r18,tr0
+	/* bubble */
+	cmpgtu r5,r2,r5
+	sub r8,r5,r2
+	blink tr0,r63
+	
+/* Note 1: To shift the result of the second divide stage so that the result
+   always fits into 32 bits, yet we still reduce the rest sufficiently
+   would require a lot of instructions to do the shifts just right.  Using
+   the full 64 bit shift result to multiply with the divisor would require
+   four extra instructions for the upper 32 bits (shift / mulu / shift / sub).
+   Fortunately, if the upper 32 bits of the shift result are nonzero, we
+   know that the rest after taking this partial result into account will
+   fit into 32 bits.  So we just clear the upper 32 bits of the rest if the
+   upper 32 bits of the partial result are nonzero.  */