X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=OPTIMIZATIONS;h=51fcb32f0e2a426469ae07f97796e3b2d1685a19;hb=51c5280a4b41f8c51d434643cde3e18af4113473;hp=99d40ea18241b3e569326c90198055f1cdd8f1df;hpb=37496d2b1c2adb6bd77b2c6c90329af871e97dd5;p=sbcl.git diff --git a/OPTIMIZATIONS b/OPTIMIZATIONS index 99d40ea..51fcb32 100644 --- a/OPTIMIZATIONS +++ b/OPTIMIZATIONS @@ -11,9 +11,6 @@ * On X86 I is represented as a tagged integer. -* EQL uses "CMP reg,reg" instead of "CMP reg,im". This causes - allocation of an extra register and an extra move. - * Unnecessary move: 3: SLOT S!11[EDX] {SB-C::VECTOR-LENGTH 1 7} => t23[EAX] 4: MOVE t23[EAX] => t24[EBX] @@ -65,11 +62,6 @@ VOP DATA-VECTOR-SET/SIMPLE-STRING V2!14[EDI] t32[EAX] t30[S2]>t33[CL] * And why two moves? -------------------------------------------------------------------------------- -#5 -(loop repeat 1.5) - -uses generic arithmetic --------------------------------------------------------------------------------- #6 09:49:05 I have found a case in those where suboptimal code is generate with nested loops, it might be moderately easy to fix that @@ -80,7 +72,6 @@ uses generic arithmetic memory location for iteration variable ;;; -*- mode: lisp -*- -;;; $Id$ ;;; http://www.bagley.org/~doug/shootout/ ;;; from Friedrich Dominicus @@ -99,21 +90,14 @@ uses generic arithmetic (incf x))))))) (format t "~A~%" x))) -------------------------------------------------------------------------------- -#7 -(defun foo (x) - (declare (optimize speed (debug 0))) - (if (< x 0) x (foo (1- x)))) - -SBCL generates a full call of FOO (but CMUCL does not). --------------------------------------------------------------------------------- #8 (defun foo (d) (declare (optimize (speed 3) (safety 0) (debug 0))) (declare (type (double-float 0d0 1d0) d)) (loop for i fixnum from 1 to 5 - for x1 double-float = (sin d) ;;; !!! - do (loop for j fixnum from 1 to 4 - sum x1 double-float))) + for x1 double-float = (sin d) ;;; !!! + do (loop for j fixnum from 1 to 4 + sum x1 double-float))) Without the marked declaration Python will use boxed representation for X1. @@ -158,3 +142,17 @@ It could be optimized to (if Y were used only once, the current compiler would optimize it) -------------------------------------------------------------------------------- +#12 +(typep (truly-the (simple-array * (*)) x) 'simple-vector) + +tests lowtag. +-------------------------------------------------------------------------------- +#13 +FAST-+/FIXNUM and similar should accept unboxed arguments in interests +of representation selection. Problem: inter-TN dependencies. +-------------------------------------------------------------------------------- +#14 +The derived type of (/ (THE (DOUBLE-FLOAT (0D0)) X) (THE (DOUBLE-FLOAT +1D0) Y)) is (DOUBLE-FLOAT 0.0d0). While it might be reasonable, it is +better to derive (DOUBLE-FLOAT (-0.0d0)). +--------------------------------------------------------------------------------