diff options
Diffstat (limited to 'riscV/Asmexpand.ml')
| -rw-r--r-- | riscV/Asmexpand.ml | 113 |
1 files changed, 110 insertions, 3 deletions
diff --git a/riscV/Asmexpand.ml b/riscV/Asmexpand.ml index 7e36abf8..810514a3 100644 --- a/riscV/Asmexpand.ml +++ b/riscV/Asmexpand.ml @@ -394,6 +394,90 @@ let expand_bswap64 d s = emit (Psrlil(X31, X s, coqint_of_camlint 56l)); emit (Porl(d, X X1, X X31)) +(* Count leading zeros. Algorithm 5-7 from Hacker's Delight, + re-rolled as a loop to produce more compact code. *) + +let expand_clz ~sixtyfour ~splitlong = + (* Input: X in X5 or (X5, X6) if splitlong + Result: N in X7 + Temporaries: S in X8, Y in X9 *) + let lbl1 = new_label() in + let lbl2 = new_label() in + (* N := bitsize of X's type (32 or 64) *) + expand_loadimm32 X7 (coqint_of_camlint + (if sixtyfour || splitlong then 64l else 32l)); + (* S := initial shift amount (16 or 32) *) + expand_loadimm32 X8 (coqint_of_camlint (if sixtyfour then 32l else 16l)); + if splitlong then begin + (* if (Xhigh == 0) goto lbl1 *) + emit (Pbeqw(X X6, X0, lbl1)); + (* N := 32 *) + expand_loadimm32 X7 (coqint_of_camlint 32l); + (* X := Xhigh *) + emit (Pmv(X5, X6)) + end; + (* lbl1: *) + emit (Plabel lbl1); + (* Y := X >> S *) + emit (if sixtyfour then Psrll(X9, X X5, X X8) else Psrlw(X9, X X5, X X8)); + (* if (Y == 0) goto lbl2 *) + emit (if sixtyfour then Pbeql(X X9, X0, lbl2) else Pbeqw(X X9, X0, lbl2)); + (* N := N - S *) + emit (Psubw(X7, X X7, X X8)); + (* X := Y *) + emit (Pmv(X5, X9)); + (* lbl2: *) + emit (Plabel lbl2); + (* S := S / 2 *) + emit (Psrliw(X8, X X8, _1)); + (* if (S != 0) goto lbl1; *) + emit (Pbnew(X X8, X0, lbl1)); + (* N := N - X *) + emit (Psubw(X7, X X7, X X5)) + +(* Count trailing zeros. Algorithm 5-14 from Hacker's Delight, + re-rolled as a loop to produce more compact code. *) + +let expand_ctz ~sixtyfour ~splitlong = + (* Input: X in X6 or (X5, X6) if splitlong + Result: N in X7 + Temporaries: S in X8, Y in X9 *) + let lbl1 = new_label() in + let lbl2 = new_label() in + (* N := bitsize of X's type (32 or 64) *) + expand_loadimm32 X7 (coqint_of_camlint + (if sixtyfour || splitlong then 64l else 32l)); + (* S := initial shift amount (16 or 32) *) + expand_loadimm32 X8 (coqint_of_camlint (if sixtyfour then 32l else 16l)); + if splitlong then begin + (* if (Xlow == 0) goto lbl1 *) + emit (Pbeqw(X X5, X0, lbl1)); + (* N := 32 *) + expand_loadimm32 X7 (coqint_of_camlint 32l); + (* X := Xlow *) + emit (Pmv(X6, X5)) + end; + (* lbl1: *) + emit (Plabel lbl1); + (* Y := X >> S *) + emit (if sixtyfour then Pslll(X9, X X6, X X8) else Psllw(X9, X X6, X X8)); + (* if (Y == 0) goto lbl2 *) + emit (if sixtyfour then Pbeql(X X9, X0, lbl2) else Pbeqw(X X9, X0, lbl2)); + (* N := N - S *) + emit (Psubw(X7, X X7, X X8)); + (* X := Y *) + emit (Pmv(X6, X9)); + (* lbl2: *) + emit (Plabel lbl2); + (* S := S / 2 *) + emit (Psrliw(X8, X X8, _1)); + (* if (S != 0) goto lbl1; *) + emit (Pbnew(X X8, X0, lbl1)); + (* N := N - most significant bit of X *) + emit (if sixtyfour then Psrlil(X6, X X6, coqint_of_camlint 63l) + else Psrliw(X6, X X6, coqint_of_camlint 31l)); + emit (Psubw(X7, X X7, X X6)) + (* Handling of compiler-inlined builtins *) let expand_builtin_inline name args res = @@ -418,10 +502,33 @@ let expand_builtin_inline name args res = assert (ah = X6 && al = X5 && rh = X5 && rl = X6); expand_bswap32 X5 X5; expand_bswap32 X6 X6 + (* Count zeros *) + | "__builtin_clz", [BA(IR a)], BR(IR res) -> + assert (a = X5 && res = X7); + expand_clz ~sixtyfour:false ~splitlong:false + | "__builtin_clzl", [BA(IR a)], BR(IR res) -> + assert (a = X5 && res = X7); + expand_clz ~sixtyfour:Archi.ptr64 ~splitlong:false + | "__builtin_clzll", [BA(IR a)], BR(IR res) -> + assert (a = X5 && res = X7); + expand_clz ~sixtyfour:true ~splitlong:false + | "__builtin_clzll", [BA_splitlong(BA(IR ah), BA(IR al))], BR(IR res) -> + assert (al = X5 && ah = X6 && res = X7); + expand_clz ~sixtyfour:false ~splitlong:true + | "__builtin_ctz", [BA(IR a)], BR(IR res) -> + assert (a = X6 && res = X7); + expand_ctz ~sixtyfour:false ~splitlong:false + | "__builtin_ctzl", [BA(IR a)], BR(IR res) -> + assert (a = X6 && res = X7); + expand_ctz ~sixtyfour:Archi.ptr64 ~splitlong:false + | "__builtin_ctzll", [BA(IR a)], BR(IR res) -> + assert (a = X6 && res = X7); + expand_ctz ~sixtyfour:true ~splitlong:false + | "__builtin_ctzll", [BA_splitlong(BA(IR ah), BA(IR al))], BR(IR res) -> + assert (al = X5 && ah = X6 && res = X7); + expand_ctz ~sixtyfour:false ~splitlong:true (* Float arithmetic *) - | "__builtin_fabs", [BA(FR a1)], BR(FR res) -> - emit (Pfabsd(res, a1)) - | "__builtin_fsqrt", [BA(FR a1)], BR(FR res) -> + | ("__builtin_fsqrt" | "__builtin_sqrt"), [BA(FR a1)], BR(FR res) -> emit (Pfsqrtd(res, a1)) | "__builtin_fmadd", [BA(FR a1); BA(FR a2); BA(FR a3)], BR(FR res) -> emit (Pfmaddd(res, a1, a2, a3)) |