Optimize decl+return into return

src/rewriter.fs

@@ -432,6 +432,9 @@ let private simplifyBlock stmts =
             Some (ForE (Some e, cond, inc, body))
         | (Expr e, While (cond, body)) -> // a=0;while(i<5);  ->  for(a=0;i<5;);
             Some (ForE(Some e, Some cond, None, body))
+        | Decl (_, [declElt]), Jump(JumpKeyword.Return, Some (Var v)) // int x=f();return x;  ->  return f();
+            when v.Name = declElt.name.Name && declElt.init.IsSome ->
+                Some (Jump(JumpKeyword.Return, declElt.init))
         | _ -> None)
 
     // Inline inner decl-less blocks. (Presence of decl could lead to redefinitions.)  a();{b();}c();  ->  a();b();c();

tests/compression_results.log

@@ -12,12 +12,12 @@ leizex.frag                               2311 =>  510.372
 lunaquatic.frag                           5257 => 1049.740
 mandelbulb.frag                           2403 =>  547.468
 ohanami.frag                              3256 =>  722.517
-orchard.frag                              5574 => 1034.487
+orchard.frag                              5537 => 1022.773
 oscars_chair.frag                         4651 =>  986.364
-robin.frag                                6333 => 1055.863
+robin.frag                                6324 => 1055.655
 slisesix.frag                             4581 =>  933.929
 terrarium.frag                            3634 =>  747.342
 the_real_party_is_in_your_pocket.frag    12168 => 1811.526
 valley_ball.glsl                          4386 =>  888.496
 yx_long_way_from_home.frag                2975 =>  610.699
-Total: 118596 => 21265.585
+Total: 118550 => 21253.664

tests/real/orchard.frag.expected

@@ -252,11 +252,6 @@ vec3 getNormal(vec3 pos,float ds)
   vec2 eps_zero=vec2(ds,0);
   return normalize(vec3(map(pos+eps_zero.xyy,0.).x,map(pos+eps_zero.yxy,0.).x,map(pos+eps_zero.yyx,0.))-c);
 }
-vec3 getSky(vec3 dir)
-{
-  vec3 col=mix(vec3(FOG_COLOUR),vec3(0,.4,.6),abs(dir.y));
-  return col;
-}
 mat3 viewMat(float ay,float az)
 {
   vec2 o,ca,sa;
@@ -284,7 +279,7 @@ void mainImage(out vec4 fragColour,vec2 fragCoord)
 
   vec3 seedDir=normalize(vec3(0,0,1));
   seedDir=viewMat(uv.y+sin(time*.5)*.4,uv.x+time*.5)*seedDir;
-  vec3 rd=seedDir,col=vec3(0),sky=getSky(rd);
+  vec3 rd=seedDir,col=vec3(0),sky=mix(vec3(FOG_COLOUR),vec3(0,.4,.6),abs(rd.y));
   float alpha=marchScene(camera,rd,fragCoord);
   vec4 mat;
   if(alpha>0.)

tests/real/robin.frag.expected

@@ -237,8 +237,7 @@ vec3 PostEffects(vec3 rgb,vec2 xy)
 vec3 CameraPath(float t)
 {
   t+=5.;
-  vec3 p=vec3(1.4+sin(t)*3.5,-.2,5.-sin(t)*2.5);
-  return p;
+  return vec3(1.4+sin(t)*3.5,-.2,5.-sin(t)*2.5);
 }
 float TweetVolume(float t)
 {

tests/unit/inline.no.expected

@@ -21,8 +21,8 @@ int arithmetic2()
 }
 int unusedVars()
 {
-  int a=arithmetic(),b=13,c=10,d=c*3;
-  return d;
+  int a=arithmetic(),b=13,c=10;
+  return c*3;
 }
 int unusedVars2()
 {
@@ -31,13 +31,12 @@ int unusedVars2()
 }
 int multiPass()
 {
-  int one=1,two=one*2,three=two+1;
-  return three;
+  int one=1,two=one*2;
+  return two+1;
 }
 float multiPass2()
 {
-  float b=9.;
-  return b;
+  return 9.;
 }
 int dont_inline_lvalue()
 {