Split up switch.S and save_restore_d8_d15.S to follow one function per file convention.
llvm-svn: 93815
diff --git a/compiler-rt/lib/arm/switch16.S b/compiler-rt/lib/arm/switch16.S
new file mode 100644
index 0000000..7255401
--- /dev/null
+++ b/compiler-rt/lib/arm/switch16.S
@@ -0,0 +1,43 @@
+//===-- switch.S - Implement switch* --------------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "../assembly.h"
+
+//
+// When compiling switch statements in thumb mode, the compiler
+// can use these __switch* helper functions The compiler emits a blx to
+// the __switch* function followed by a table of displacements for each
+// case statement. On entry, R0 is the index into the table. The __switch*
+// function uses the return address in lr to find the start of the table.
+// The first entry in the table is the count of the entries in the table.
+// It then uses R0 to index into the table and get the displacement of the
+// address to jump to. If R0 is greater than the size of the table, it jumps
+// to the last entry in the table. Each displacement in the table is actually
+// the distance from lr to the label, thus making the tables PIC.
+
+
+ .text
+ .syntax unified
+
+//
+// The table contains signed 2-byte sized elements which are 1/2 the distance
+// from lr to the target label.
+//
+DEFINE_COMPILERRT_PRIVATE_FUNCTION(__switch16)
+ ldrh ip, [lr, #-1] // get first 16-bit word in table
+ cmp r0, ip // compare with index
+ add r0, lr, r0, lsl #1 // compute address of element in table
+ ldrshcc r0, [r0, #1] // load 16-bit element if r0 is in range
+ add ip, lr, ip, lsl #1 // compute address of last element in table
+ ldrshhs r0, [ip, #1] // load 16-bit element if r0 out of range
+ add ip, lr, r0, lsl #1 // compute label = lr + element*2
+ bx ip // jump to computed label
+
+ // tell linker it can break up file at label boundaries
+ .subsections_via_symbols