Add some notes

llvm-svn: 18911

lib/Target/SparcV8/README.txt

@@ -53,7 +53,27 @@ To-do
 
 * support shl on longs (fourinarow needs this)
 * support casting 64-bit integers to FP types (fhourstones needs this)
-* support FP rem
+* support FP rem (call fmod)
+
+* Eliminate srl/sll by zero bits like this:
+        sll %l0, 0, %l0
+        srl %l0, 0, %o0
+
+  We think these are only used by V9 to clear off the top 32 bits of a reg,
+  so they are not needed.
+
+* Keep the address of the constant pool in a register instead of forming its
+  address all of the time.
+
+* Change code like this:
+        or      %o0, %lo(.CPI_main_0), %o0
+        ld      [%o0+0], %o0
+  into:
+        ld	[%o0+%lo(.CPI_main_0)], %o0
+  for constant pool access.
+
+* We can fold small constant offsets into the %hi/%lo references to constant
+  pool addresses as well.
 
 $Date$