Changeset 14998 for trunk/source/compiler/X86/X8632/x8632-vinsns.lisp

Timestamp:

Sep 24, 2011, 8:36:16 AM (9 years ago)

Author:

gb

Message:

Conditionally (using *x862-generate-casejump*, which defaults to false
for now) enable code to do constant-time CASE for certain types/ranges
of keys via a jump table.

Make the X86 disassembler recognize references to labels referenced from
the jump table (though it doesn't yet do anything to show the jump table
itself.)

This is about as far along as the ARM backend has been for the last few
months; the mechanics of dispatching through the jump table seem to be
correct, but the code generated at each case label is only correct in
certain circumstances.

File:

• trunk/source/compiler/X86/X8632/x8632-vinsns.lisp (modified) (1 diff)

trunk/source/compiler/X86/X8632/x8632-vinsns.lisp

@@ -4217 +4217 @@
   (movl (:@ (:% x8632::ebp)) (:% x8632::ebp)))
 
+(define-x8632-vinsn (cjmp :branch) (((reg :lisp))
+                                    ((reg :lisp)
+                                     (minval :s32const)
+                                     (maxval :u32const)
+                                     (default :label))
+                                    ((temp :s32)
+                                    (rjmp :lisp)))
+  (testl (:$l x8664::fixnummask) (:%l reg))
+  (jne default)
+  ((:not (:pred zerop minval))
+   (subl (:$l minval) (:%l reg)))
+  (cmpl (:$l maxval) (:%l reg))
+  (ja default)
+  (movl (:%l reg) (:%l temp))
+  (shrl (:%l temp))
+  (movl (:@ (:^ :jtab) (:%l x8632::fn) (:%l temp)) (:%l temp))
+  (leal (:@ (:%l x8632::fn) (:%l temp)) (:%l rjmp))
+  (jmp (:%l rjmp))
+  (:uuo-section)
+  (:align 2)
+  (:long (:apply 1+ (:apply ash maxval (- x8632::fixnumshift))))
+  :jtab)
+
+(define-x8632-vinsn jtabentry (()
+                               ((label :label)))
+  (:uuo-section)
+  (:long (:^ label)))
+
 (queue-fixup
  (fixup-x86-vinsn-templates