more cleanups

pocketfft_hdronly.h

@@ -198,6 +198,8 @@ template<typename T> struct cmplx {
   cmplx(T r_, T i_) : r(r_), i(i_) {}
   void Set(T r_, T i_) { r=r_; i=i_; }
   void Set(T r_) { r=r_; i=T(0); }
+  void Split(T &r_, T &i_) const { r_=r; i_=i; }
+  void SplitConj(T &r_, T &i_) const { r_=r; i_=-i; }
   cmplx &operator+= (const cmplx &other)
     { r+=other.r; i+=other.i; return *this; }
   template<typename T2>cmplx &operator*= (T2 other)
@@ -2348,10 +2350,7 @@ template<typename T0> class T_dst1
       arr<T> tmp(N);
       tmp[0] = tmp[n+1] = c[0]*0;
       for (size_t i=0; i<n; ++i)
-        {
-        tmp[i+1] = c[i];
-        tmp[N-1-i] = -c[i];
-        }
+        { tmp[i+1]=c[i]; tmp[N-1-i]=-c[i]; }
       fftplan.forward(tmp.data(), fct);
       for (size_t i=0; i<n; ++i)
         c[i] = -tmp[2*i+2];
@@ -2366,63 +2365,6 @@ template<typename T0> class T_dcst23
     pocketfft_r<T0> fftplan;
     vector<T0> twiddle;
 
-    template<typename T> POCKETFFT_NOINLINE void exec2(T c[], T0 fct,
-      bool ortho, bool cosine) const
-      {
-      constexpr T0 sqrt2=T0(1.414213562373095048801688724209698L);
-      size_t N=length();
-      size_t NS2 = (N+1)/2;
-      if (!cosine)
-        for (size_t k=1; k<N; k+=2)
-          c[k] = -c[k];
-      for (size_t k=1; k<N-1; k+=2)
-        {
-        T tmp  = T0(0.5)*(c[k]+c[k+1]);
-        c[k+1] = T0(0.5)*(c[k+1]-c[k]);
-        c[k]   = tmp;
-        }
-      fftplan.backward(c, fct);
-      for (size_t k=1, kc=N-1; k<NS2; ++k, --kc)
-        {
-        T t1 = twiddle[k-1]*c[kc]+twiddle[kc-1]*c[k];
-        T t2 = twiddle[k-1]*c[k]-twiddle[kc-1]*c[kc];
-        c[k] = t1+t2; c[kc]=t1-t2;
-        }
-      if ((N&1)==0)
-        c[NS2] = twiddle[NS2-1]*(c[NS2]+c[NS2]);
-      c[0] *= 2;
-      if (!cosine)
-        for (size_t k=0, kc=N-1; k<kc; ++k, --kc)
-          swap(c[k], c[kc]);
-      if (ortho) c[0]/=sqrt2;
-      }
-
-    template<typename T> POCKETFFT_NOINLINE void exec3(T c[], T0 fct,
-      bool ortho, bool cosine) const
-      {
-      constexpr T0 sqrt2=T0(1.414213562373095048801688724209698L);
-      size_t N=length();
-      size_t NS2 = (N+1)/2;
-      if (ortho) c[0]*=sqrt2;
-      if (!cosine)
-        for (size_t k=0, kc=N-1; k<NS2; ++k, --kc)
-          swap(c[k], c[kc]);
-      for (size_t k=1, kc=N-1; k<NS2; ++k, --kc)
-        {
-        T t1=c[k]+c[kc], t2=c[k]-c[kc];
-        c[k] = twiddle[k-1]*t2+twiddle[kc-1]*t1;
-        c[kc]= twiddle[k-1]*t1-twiddle[kc-1]*t2;
-        }
-      if ((N&1)==0)
-        c[NS2] = 2*twiddle[NS2-1]*c[NS2];
-      fftplan.forward(c, fct);
-      for (size_t k=1; k<N-1; k+=2)
-        MPINPLACE(c[k], c[k+1]);
-      if (!cosine)
-        for (size_t k=1; k<N; k+=2)
-          c[k] = -c[k];
-      }
-
   public:
     POCKETFFT_NOINLINE T_dcst23(size_t length)
       : fftplan(length), twiddle(length)
@@ -2434,7 +2376,55 @@ template<typename T0> class T_dcst23
 
     template<typename T> POCKETFFT_NOINLINE void exec(T c[], T0 fct, bool ortho,
       int type, bool cosine) const
-      { type==2 ? exec2(c, fct, ortho, cosine) : exec3(c, fct, ortho, cosine); }
+      {
+      constexpr T0 sqrt2=T0(1.414213562373095048801688724209698L);
+      size_t N=length();
+      size_t NS2 = (N+1)/2;
+      if (type==2)
+        {
+        if (!cosine)
+          for (size_t k=1; k<N; k+=2)
+            c[k] = -c[k];
+        c[0] *= 2;
+        if ((N&1)==0) c[N-1]*=2;
+        for (size_t k=1; k<N-1; k+=2)
+          MPINPLACE(c[k+1], c[k]);
+        fftplan.backward(c, fct);
+        for (size_t k=1, kc=N-1; k<NS2; ++k, --kc)
+          {
+          T t1 = twiddle[k-1]*c[kc]+twiddle[kc-1]*c[k];
+          T t2 = twiddle[k-1]*c[k]-twiddle[kc-1]*c[kc];
+          c[k] = T0(0.5)*(t1+t2); c[kc]=T0(0.5)*(t1-t2);
+          }
+        if ((N&1)==0)
+          c[NS2] *= twiddle[NS2-1];
+        if (!cosine)
+          for (size_t k=0, kc=N-1; k<kc; ++k, --kc)
+            swap(c[k], c[kc]);
+        if (ortho) c[0]/=sqrt2;
+        }
+      else
+        {
+        if (ortho) c[0]*=sqrt2;
+        if (!cosine)
+          for (size_t k=0, kc=N-1; k<NS2; ++k, --kc)
+            swap(c[k], c[kc]);
+        for (size_t k=1, kc=N-1; k<NS2; ++k, --kc)
+          {
+          T t1=c[k]+c[kc], t2=c[k]-c[kc];
+          c[k] = twiddle[k-1]*t2+twiddle[kc-1]*t1;
+          c[kc]= twiddle[k-1]*t1-twiddle[kc-1]*t2;
+          }
+        if ((N&1)==0)
+          c[NS2] *= 2*twiddle[NS2-1];
+        fftplan.forward(c, fct);
+        for (size_t k=1; k<N-1; k+=2)
+          MPINPLACE(c[k], c[k+1]);
+        if (!cosine)
+          for (size_t k=1; k<N; k+=2)
+            c[k] = -c[k];
+        }
+      }
 
     size_t length() const { return fftplan.length(); }
   };
@@ -3120,17 +3110,11 @@ template<typename T> POCKETFFT_NOINLINE void general_c2r(
       if (forward)
         for (; i<len-1; i+=2, ++ii)
           for (size_t j=0; j<vlen; ++j)
-            {
-            tdatav[i  ][j] = in[it.iofs(j,ii)].r;
-            tdatav[i+1][j] = -in[it.iofs(j,ii)].i;
-            }
+            in[it.iofs(j,ii)].SplitConj(tdatav[i][j], tdatav[i+1][j]);
       else
         for (; i<len-1; i+=2, ++ii)
           for (size_t j=0; j<vlen; ++j)
-            {
-            tdatav[i  ][j] = in[it.iofs(j,ii)].r;
-            tdatav[i+1][j] = in[it.iofs(j,ii)].i;
-            }
+            in[it.iofs(j,ii)].Split(tdatav[i][j], tdatav[i+1][j]);
       if (i<len)
         for (size_t j=0; j<vlen; ++j)
           tdatav[i][j] = in[it.iofs(j,ii)].r;
@@ -3150,16 +3134,10 @@ template<typename T> POCKETFFT_NOINLINE void general_c2r(
     size_t i=1, ii=1;
     if (forward)
       for (; i<len-1; i+=2, ++ii)
-        {
-        tdata[i  ] =  in[it.iofs(ii)].r;
-        tdata[i+1] = -in[it.iofs(ii)].i;
-        }
+        in[it.iofs(ii)].SplitConj(tdata[i], tdata[i+1]);
     else
       for (; i<len-1; i+=2, ++ii)
-        {
-        tdata[i  ] = in[it.iofs(ii)].r;
-        tdata[i+1] = in[it.iofs(ii)].i;
-        }
+        in[it.iofs(ii)].Split(tdata[i], tdata[i+1]);
     if (i<len)
       tdata[i] = in[it.iofs(ii)].r;
     }