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authorKim Phillips <kim.phillips@freescale.com>2013-11-06 08:15:24 +0400
committerRussell King <rmk+kernel@arm.linux.org.uk>2013-12-29 16:32:45 +0400
commit017f161a55b48807a73fc9dff0b69f081bf43ee3 (patch)
tree1c440562e87f4c394d483935486019cc9854ffe8 /arch/arm/lib/bswapsdi2.S
parent03aa6580e336c19e923372a3b6b72a300f24880c (diff)
downloadlinux-017f161a55b48807a73fc9dff0b69f081bf43ee3.tar.xz
ARM: 7877/1: use built-in byte swap function
Enable the compiler intrinsic for byte swapping on arch ARM. This allows the compiler to detect and be able to optimize out byte swappings, and has a very modest benefit on vmlinux size (Linaro gcc 4.8): text data bss dec hex filename 2840310 123932 61960 3026202 2e2d1a vmlinux-lart #orig 2840152 123932 61960 3026044 2e2c7c vmlinux-lart #builtin-bswap 6473120 314840 5616016 12403976 bd4508 vmlinux-mxs #orig 6472586 314848 5616016 12403450 bd42fa vmlinux-mxs #builtin-bswap 7419872 318372 379556 8117800 7bde28 vmlinux-imx_v6_v7 #orig 7419170 318364 379556 8117090 7bdb62 vmlinux-imx_v6_v7 #builtin-bswap Signed-off-by: Kim Phillips <kim.phillips@freescale.com> Reviewed-by: Nicolas Pitre <nico@linaro.org> Acked-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/lib/bswapsdi2.S')
-rw-r--r--arch/arm/lib/bswapsdi2.S36
1 files changed, 36 insertions, 0 deletions
diff --git a/arch/arm/lib/bswapsdi2.S b/arch/arm/lib/bswapsdi2.S
new file mode 100644
index 000000000000..9fcdd154eff9
--- /dev/null
+++ b/arch/arm/lib/bswapsdi2.S
@@ -0,0 +1,36 @@
+#include <linux/linkage.h>
+
+#if __LINUX_ARM_ARCH__ >= 6
+ENTRY(__bswapsi2)
+ rev r0, r0
+ bx lr
+ENDPROC(__bswapsi2)
+
+ENTRY(__bswapdi2)
+ rev r3, r0
+ rev r0, r1
+ mov r1, r3
+ bx lr
+ENDPROC(__bswapdi2)
+#else
+ENTRY(__bswapsi2)
+ eor r3, r0, r0, ror #16
+ mov r3, r3, lsr #8
+ bic r3, r3, #0xff00
+ eor r0, r3, r0, ror #8
+ mov pc, lr
+ENDPROC(__bswapsi2)
+
+ENTRY(__bswapdi2)
+ mov ip, r1
+ eor r3, ip, ip, ror #16
+ eor r1, r0, r0, ror #16
+ mov r1, r1, lsr #8
+ mov r3, r3, lsr #8
+ bic r3, r3, #0xff00
+ bic r1, r1, #0xff00
+ eor r1, r1, r0, ror #8
+ eor r0, r3, ip, ror #8
+ mov pc, lr
+ENDPROC(__bswapdi2)
+#endif