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at 2024-03-22T15:15:57+00:00

Fix #283: Add VOP for integer-length for an (unsigned-byte 32) arg

Merge branch 'issue-283-unsigned-integer-length-vop' into 'master'

Fix #283: Add VOP for integer-length for an (unsigned-byte 32) arg

Closes #283

See merge request cmucl/cmucl!194
     (inst xor res res)

     DONE))

 

+(define-vop (unsigned-byte-32-len)

+  (:translate integer-length)

+  (:note _N"inline (unsigned-byte 32) integer-length")

+  (:policy :fast-safe)

+  (:args (arg :scs (unsigned-reg)))

+  (:arg-types unsigned-num)

+  (:results (res :scs (any-reg)))

+  (:result-types positive-fixnum)

+  (:generator 30

+    (move res arg)

+    ;; The Intel docs say that BSR leaves the destination register

+    ;; undefined if the source is 0.  But AMD64 says the destination

+    ;; register is unchanged.  This also appears to be the case for

+    ;; GCC and LLVM.

+    (inst bsr res res)

+    (inst jmp :z DONE)

+    ;; The result of BSR is one too small for what we want, so

+    ;; increment the result.

+    (inst inc res)

+    (inst shl res 2)

+    DONE))

+

 (define-vop (unsigned-byte-32-count)

   (:translate logcount)

   (:note _N"inline (unsigned-byte 32) logcount")

 msgid "inline (signed-byte 32) integer-length"

 msgstr ""

 

+#: src/compiler/x86/arith.lisp

+msgid "inline (unsigned-byte 32) integer-length"

+msgstr ""

+

 #: src/compiler/x86/arith.lisp

 msgid "inline (unsigned-byte 32) logcount"

 msgstr ""

Raymond Toy pushed to branch master at cmucl / cmucl

Commits:

2 changed files:

Changes: