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SIMD für Stufe 1 der FFT

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unknown 2015-03-10 15:11:56 +01:00
parent 818574c62e
commit 04828296f7
3 changed files with 109 additions and 19 deletions
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2
fft-org.c
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@ -126,6 +126,7 @@ int fix_fft_org(fixed fr[], fixed fi[], int m, int inverse)
wr >>= 1;
wi >>= 1;
}
for(i=m; i<n; i+=istep)
{
@ -148,6 +149,7 @@ int fix_fft_org(fixed fr[], fixed fi[], int m, int inverse)
fi[i] = qi + ti;
}
}
--k;
l = istep;
}

49
fft.c
View File

@ -112,26 +112,41 @@ int fix_fft(fixed fr[], fixed fi[], int m, int inverse)
istep = l << 1; //step width of current butterfly
FFT_reg reg;
FFT_reg_simd simd_r, simd_i;
fixed *reg_s = ((fixed*) &reg);
for(m=0; m<n; m+=istep)
if(l == 1)
{
for(i=m; i<m+l; ++i)
{
j = i + l;
reg_s[3] = fr[i];
reg_s[2] = fr[j];
reg_s[1] = fi[i];
reg_s[0] = fi[j];
FFT_calc(reg, i << k, (xtbool) shift, inverse);
fr[i] = reg_s[3];
fr[j] = reg_s[2];
fi[i] = reg_s[1];
fi[j] = reg_s[0];
}
for(i=0; i<n; i+=8)
{
simd_r = FFT_simd_load(fr, i);
simd_i = FFT_simd_load(fi, i);
FFT_simd_first(simd_r, simd_i, (xtbool) shift);
FFT_simd_store(fr, i, simd_r);
FFT_simd_store(fi, i, simd_i);
}
}
else
{
for(m=0; m<n; m+=istep)
{
for(i=m; i<m+l; ++i)
{
j = i + l;
reg_s[3] = fr[i];
reg_s[2] = fr[j];
reg_s[1] = fi[i];
reg_s[0] = fi[j];
FFT_calc(reg, i << k, (xtbool) shift, inverse);
fr[i] = reg_s[3];
fr[j] = reg_s[2];
fi[i] = reg_s[1];
fi[j] = reg_s[0];
}
}
}
--k;
l = istep;

77
fft_inst.tie
View File

@ -132,6 +132,62 @@ table SIN_wave 16 1024 {
regfile FFT_reg 64 2 fftv
regfile FFT_reg_simd 128 2 fftsv
function [31:0] FFT_var_shift([31:0] data, [3:0] sh)
{
assign FFT_var_shift = TIEmux(sh,
data[31:0],
{data[30:0], 1'b0},
{data[29:0], 2'b0},
{data[28:0], 3'b0},
{data[27:0], 4'b0},
{data[26:0], 5'b0},
{data[25:0], 6'b0},
{data[24:0], 7'b0},
{data[23:0], 8'b0},
{data[22:0], 9'b0},
{data[21:0], 10'b0},
{data[20:0], 11'b0},
{data[19:0], 12'b0},
{data[18:0], 13'b0},
{data[17:0], 14'b0},
{data[16:0], 15'b0}
);
}
operation FFT_simd_load {in AR *base, in AR offset, out FFT_reg_simd data} {out VAddr, in MemDataIn128}
{
assign VAddr = TIEadd(base, {offset[30:0], 1'b0}, 1'b0);
wire [15:0] o1 = MemDataIn128[15:0];
wire [15:0] o2 = MemDataIn128[31:16];
wire [15:0] o3 = MemDataIn128[47:32];
wire [15:0] o4 = MemDataIn128[63:48];
wire [15:0] o5 = MemDataIn128[79:64];
wire [15:0] o6 = MemDataIn128[95:80];
wire [15:0] o7 = MemDataIn128[111:96];
wire [15:0] o8 = MemDataIn128[127:112];
assign data = {o1, o2, o3, o4, o5, o6, o7, o8 };
}
operation FFT_simd_store {in AR *base, in AR offset, in FFT_reg_simd data} {out VAddr, out MemDataOut128}
{
assign VAddr = TIEadd(base, {offset[30:0], 1'b0}, 1'b0);
wire [15:0] o1 = data[15:0];
wire [15:0] o2 = data[31:16];
wire [15:0] o3 = data[47:32];
wire [15:0] o4 = data[63:48];
wire [15:0] o5 = data[79:64];
wire [15:0] o6 = data[95:80];
wire [15:0] o7 = data[111:96];
wire [15:0] o8 = data[127:112];
assign MemDataOut128 = {o1, o2, o3, o4, o5, o6, o7, o8 };
}
operation FFT_shift_check {in AR *base, in AR offset, out AR needs_shift} {out VAddr, in MemDataIn128}
{
assign VAddr = TIEadd(base, offset[31:1], 1'b0);
@ -243,6 +299,22 @@ operation FFT_calc {inout FFT_reg data, in AR i, in BR shift, in BR inverse} {}
assign data = FFT_butterfly(data, wr, wi, shift);
}
// 4 butterflies at once
operation FFT_simd_first {inout FFT_reg_simd fr, inout FFT_reg_simd fi, in BR shift} {}
{
wire [15:0] wr = TIEmux(shift, 16'h7fff, 16'h3fff);
wire [15:0] wi = 16'b0;
wire [63:0] res1 = FFT_butterfly({fr[127:96], fi[127:96]}, wr, wi, shift);
wire [63:0] res2 = FFT_butterfly({fr[95:64], fi[95:64]}, wr, wi, shift);
wire [63:0] res3 = FFT_butterfly({fr[63:32], fi[63:32]}, wr, wi, shift);
wire [63:0] res4 = FFT_butterfly({fr[31:0], fi[31:0]}, wr, wi, shift);
assign fr = { res1[63:32], res2[63:32], res3[63:32], res4[63:32] };
assign fi = { res1[31:0], res2[31:0], res3[31:0], res4[31:0] };
}
////////////////////////////////////////////////////////////////////////////
//
// Generated by XPRES v4.0.4
@ -321,11 +393,11 @@ slot_opcodes Inst {
FFT_bit_reverse, FFT_calc, ld.FFT_reg,
mv.FFT_reg, st.FFT_reg }
slot_opcodes flix64_0_slot0 {
ADD, BEQZ, BGEU, BLTU, BNEZ, L16SI, MOV.N, NOP, S16I, SEXT, SUB, FFT_shift_check }
ADD, BEQZ, BGEU, BLTU, BNEZ, L16SI, MOV.N, NOP, S16I, SEXT, SUB, FFT_shift_check, FFT_simd_load, FFT_simd_store }
slot_opcodes flix64_0_slot1 {
ADD, ADDX2, MOV.N, MOVNEZ, NEG, NOP }
slot_opcodes flix64_0_slot2 {
ADD, L16SI, NOP, S16I, SUB, FFT_shift_check }
ADD, L16SI, NOP, S16I, SUB, FFT_shift_check, FFT_simd_load, FFT_simd_store }
//--------------------------------------------------------------------------
@ -335,3 +407,4 @@ slot_opcodes flix64_0_slot2 {
//--------------------------------------------------------------------------
ctype FFT_reg 64 64 FFT_reg default
ctype FFT_reg_simd 128 128 FFT_reg_simd default