Add qemu 2.4.0

[kvmfornfv.git] / qemu / roms / u-boot / arch / arc / lib / strcmp.S

diff --git a/qemu/roms/u-boot/arch/arc/lib/strcmp.S b/qemu/roms/u-boot/arch/arc/lib/strcmp.S
new file mode 100644 (file)
index 0000000..8cb7d2f
--- /dev/null
+++ b/qemu/roms/u-boot/arch/arc/lib/strcmp.S
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2014 Synopsys, Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+/*
+ * This is optimized primarily for the ARC700.
+ * It would be possible to speed up the loops by one cycle / word
+ * respective one cycle / byte by forcing double source 1 alignment, unrolling
+ * by a factor of two, and speculatively loading the second word / byte of
+ * source 1; however, that would increase the overhead for loop setup / finish,
+ * and strcmp might often terminate early.
+ */
+
+.global strcmp
+.align 4
+strcmp:
+       or      %r2, %r0, %r1
+       bmsk_s  %r2, %r2, 1
+       brne    %r2, 0, .Lcharloop
+       mov_s   %r12, 0x01010101
+       ror     %r5, %r12
+.Lwordloop:
+       ld.ab   %r2, [%r0, 4]
+       ld.ab   %r3, [%r1, 4]
+       nop_s
+       sub     %r4, %r2, %r12
+       bic     %r4, %r4, %r2
+       and     %r4, %r4, %r5
+       brne    %r4, 0, .Lfound0
+       breq    %r2 ,%r3, .Lwordloop
+#ifdef __LITTLE_ENDIAN__
+       xor     %r0, %r2, %r3   /* mask for difference */
+       sub_s   %r1, %r0, 1
+       bic_s   %r0, %r0, %r1   /* mask for least significant difference bit */
+       sub     %r1, %r5, %r0
+       xor     %r0, %r5, %r1   /* mask for least significant difference byte */
+       and_s   %r2, %r2, %r0
+       and_s   %r3, %r3, %r0
+#endif /* _ENDIAN__ */
+       cmp_s   %r2, %r3
+       mov_s   %r0, 1
+       j_s.d   [%blink]
+       bset.lo %r0, %r0, 31
+
+       .balign 4
+#ifdef __LITTLE_ENDIAN__
+.Lfound0:
+       xor     %r0, %r2, %r3   /* mask for difference */
+       or      %r0, %r0, %r4   /* or in zero indicator */
+       sub_s   %r1, %r0, 1
+       bic_s   %r0, %r0, %r1   /* mask for least significant difference bit */
+       sub     %r1, %r5, %r0
+       xor     %r0, %r5, %r1   /* mask for least significant difference byte */
+       and_s   %r2, %r2, %r0
+       and_s   %r3, %r3, %r0
+       sub.f   %r0, %r2, %r3
+       mov.hi  %r0, 1
+       j_s.d   [%blink]
+       bset.lo %r0, %r0, 31
+#else /* __BIG_ENDIAN__ */
+       /*
+        * The zero-detection above can mis-detect 0x01 bytes as zeroes
+        * because of carry-propagateion from a lower significant zero byte.
+        * We can compensate for this by checking that bit0 is zero.
+        * This compensation is not necessary in the step where we
+        * get a low estimate for r2, because in any affected bytes
+        * we already have 0x00 or 0x01, which will remain unchanged
+        * when bit 7 is cleared.
+        */
+       .balign 4
+.Lfound0:
+       lsr     %r0, %r4, 8
+       lsr_s   %r1, %r2
+       bic_s   %r2, %r2, %r0   /* get low estimate for r2 and get ... */
+       bic_s   %r0, %r0, %r1   /* <this is the adjusted mask for zeros> */
+       or_s    %r3, %r3, %r0   /* ... high estimate r3 so that r2 > r3 will */
+       cmp_s   %r3, %r2        /* ... be independent of trailing garbage */
+       or_s    %r2, %r2, %r0   /* likewise for r3 > r2 */
+       bic_s   %r3, %r3, %r0
+       rlc     %r0, 0          /* r0 := r2 > r3 ? 1 : 0 */
+       cmp_s   %r2, %r3
+       j_s.d   [%blink]
+       bset.lo %r0, %r0, 31
+#endif /* _ENDIAN__ */
+
+       .balign 4
+.Lcharloop:
+       ldb.ab  %r2,[%r0,1]
+       ldb.ab  %r3,[%r1,1]
+       nop_s
+       breq    %r2, 0, .Lcmpend
+       breq    %r2, %r3, .Lcharloop
+.Lcmpend:
+       j_s.d   [%blink]
+       sub     %r0, %r2, %r3