Merge for-declaration with the previous declaration (#371)

int a=2; for (int b=3; ...)
->
 int a=2, b=3; for (; ...)

src/rewriter.fs

@@ -375,6 +375,9 @@ module private RewriterImpl =
         | []-> []
         | Decl(ty1, li1) :: Decl(ty2, li2) :: l when ty1 = ty2 ->
             squeezeConsecutiveDeclarations (Decl(ty1, li1 @ li2) :: l)
+        // int a=2; for (int b=3; ...) -> int a=2, b=3; for (; ...)
+        | Decl(ty1, li1) :: ForD((ty2, li2), cond, inc, body) :: l when ty1 = ty2 ->
+            squeezeConsecutiveDeclarations (Decl(ty1, li1 @ li2) :: ForE(None, cond, inc, body) :: l)
         | e::l -> e :: squeezeConsecutiveDeclarations l
 
     // Squeeze top-level declarations, e.g. uniforms

tests/compression_results.log

@@ -3,22 +3,22 @@ mouton/mouton.vert...                    16951 => 2447.462
 audio-flight-v2.frag                      4509 =>  881.311
 buoy.frag                                 4051 =>  607.428
 controllable-machinery.frag               7703 => 1216.907
-ed-209.frag                               7702 => 1341.619
-elevated.hlsl                             3405 =>  603.218
-endeavour.frag                            2589 =>  529.811
+ed-209.frag                               7697 => 1340.743
+elevated.hlsl                             3400 =>  602.269
+endeavour.frag                            2584 =>  532.679
 from-the-seas-to-the-stars.frag          14250 => 2308.842
 frozen-wasteland.frag                     4566 =>  806.475
 kinder_painter.frag                       2847 =>  442.771
 leizex.frag                               2270 =>  510.375
-lunaquatic.frag                           5239 => 1044.087
-mandelbulb.frag                           2347 =>  537.664
+lunaquatic.frag                           5234 => 1043.382
+mandelbulb.frag                           2342 =>  537.655
 ohanami.frag                              3255 =>  723.732
-orchard.frag                              5510 => 1027.042
+orchard.frag                              5505 => 1027.273
 oscars_chair.frag                         4651 =>  986.364
-robin.frag                                6257 => 1047.684
+robin.frag                                6254 => 1047.419
 slisesix.frag                             4549 =>  913.642
 terrarium.frag                            3593 =>  741.557
 the_real_party_is_in_your_pocket.frag    12087 => 1780.714
 valley_ball.glsl                          4307 =>  881.820
 yx_long_way_from_home.frag                2942 =>  598.650
-Total: 134416 => 23495.003
+Total: 134383 => 23495.298

tests/real/ed-209.frag.expected

@@ -310,8 +310,8 @@ MarchData map(vec3 p)
 float calcShadow(vec3 p,vec3 lightPos)
 {
   lightPos=normalize(lightPos-p);
-  float res=1.,t=.1;
-  for(float i=0.;i<SHADOW_STEPS;i++)
+  float res=1.,t=.1,i=0.;
+  for(;i<SHADOW_STEPS;i++)
     {
       float h=map(p+lightPos*t).d;
       res=min(res,12.*h/t);

tests/real/elevated.hlsl.expected

@@ -25,12 +25,12 @@ const char *elevated_hlsl =
  "float D(float2 f,float y)"
  "{"
    "float2 z=0;"
-   "float x=0,w=3;"
-   "for(float r=0;r<y;r++)"
+   "float x=0,w=3,t=0;"
+   "for(;t<y;t++)"
      "{"
-       "float3 t=D(.25*f);"
-       "z+=t.yz;"
-       "x+=(w*=.5)*t.x/(1+mul(z,z));"
+       "float3 s=D(.25*f);"
+       "z+=s.yz;"
+       "x+=(w*=.5)*s.x/(1+mul(z,z));"
        "f=mul(float2x2(1.6,-1.2,1.2,1.6),f);"
      "}"
    "return x;"

tests/real/endeavour.frag.expected

@@ -22,8 +22,8 @@ void lfnoise(vec2 t,out float num)
 void mfnoise(vec2 x,float fmin,float fmax,float alpha,out float num)
 {
   num=0.;
-  float a=1.,nf=0.,buf;
-  for(float f=fmin;f<fmax;f*=2.)
+  float a=1.,nf=0.,buf,f=fmin;
+  for(;f<fmax;f*=2.)
     lfnoise(f*x,buf),num+=a*buf,a*=alpha,nf+=1.;
   num*=(1.-alpha)/(1.-pow(alpha,nf));
 }

tests/real/lunaquatic.frag.expected

@@ -60,8 +60,8 @@ vec3 getWaterNormal(vec3 p)
 }
 int traceTerrain(vec3 ro,vec3 rd,float maxt,out float depth)
 {
-  float lh,ly,delt=0.;
-  for(float t=.1;t<maxt;t+=delt)
+  float lh,ly,delt=0.,t=.1;
+  for(;t<maxt;t+=delt)
     {
       ro+=rd*delt;
       depth=height(ro.xz);

tests/real/mandelbulb.expected

@@ -60,8 +60,8 @@ const char *mandelbulb_frag =
      "s.y=1e20;"
    "float x;"
    "vec3 z;"
-   "float t=1./sqrt(2.);"
-   "for(float d=s.x;d<s.y;)"
+   "float t=1./sqrt(2.),d=s.x;"
+   "for(;d<s.y;)"
      "{"
        "vec3 w=v+o*d;"
        "float r=clamp(.001*d*t,1e-6,.005),g=r*.1;"

tests/real/orchard.frag.expected

@@ -198,8 +198,8 @@ float shadow(vec3 ro,vec3 rd,float dis)
 }
 float calcOcc(vec3 pos,vec3 nor,float d)
 {
-  float occ=0.,sca=1.;
-  for(float h=.05;h<.3;h+=.07)
+  float occ=0.,sca=1.,h=.05;
+  for(;h<.3;h+=.07)
     {
       vec3 opos=pos+h*nor;
       float d=map(opos,d).x;

tests/real/robin.frag.expected

@@ -195,8 +195,8 @@ float Scene(vec3 rO,vec3 rD,vec2 fragCoord)
 {
   float t=2.+.1*Hash(fragCoord.xy*fract(iTime)),alphaAcc=0.;
   vec3 p=vec3(0);
-  int hits=0;
-  for(int j=0;j<40;j++)
+  int hits=0,j=0;
+  for(;j<40;j++)
     {
       if(hits==8||alphaAcc>=1.||t>45.)
         break;

tests/unit/blocks.expected

@@ -18,8 +18,8 @@ const char *blocks_frag =
  "int k=5;"
  "float test_for()"
  "{"
-   "int foo=2,n=0;"
-   "for(int i=0;i<4;i++)"
+   "int foo=2,n=0,i=0;"
+   "for(;i<4;i++)"
      "foo+=i;"
    "for(foo++;n<4;n++)"
      "{"

tests/unit/loop.frag.expected

@@ -10,8 +10,8 @@ const char *loop_frag =
  "float a;"
  "void main()"
  "{"
-   "float c;"
-   "for(float d=0.;d<50.;++d)"
+   "float c,d=0.;"
+   "for(;d<50.;++d)"
      "c+=cos(d);"
    "float b;"
    "for(b=0.;b<50.;++b)"