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| author | Tristan Gingold <tgingold@free.fr> | 2019-12-31 18:55:44 +0100 |
|---|---|---|
| committer | Tristan Gingold <tgingold@free.fr> | 2019-12-31 18:57:44 +0100 |
| commit | 3485a2054df425a54796ce69f28d19b6eea2b868 (patch) | |
| tree | 58293caff9f2426c061cd621432cc56fa9ecabd4 | |
| parent | 03e71f74ace9dbd543435b5f94df87b83bb7d54f (diff) | |
| download | ghdl-3485a2054df425a54796ce69f28d19b6eea2b868.tar.gz ghdl-3485a2054df425a54796ce69f28d19b6eea2b868.tar.bz2 ghdl-3485a2054df425a54796ce69f28d19b6eea2b868.zip | |
synth-environment: also optimize mux merge for sub-nets.
| -rw-r--r-- | src/synth/netlists-utils.adb | 28 | ||||
| -rw-r--r-- | src/synth/netlists-utils.ads | 5 | ||||
| -rw-r--r-- | src/synth/synth-environment.adb | 2 |
3 files changed, 34 insertions, 1 deletions
diff --git a/src/synth/netlists-utils.adb b/src/synth/netlists-utils.adb index 4a189b39e..59eb086d5 100644 --- a/src/synth/netlists-utils.adb +++ b/src/synth/netlists-utils.adb @@ -230,6 +230,34 @@ package body Netlists.Utils is Free_Instance (Inst); end Disconnect_And_Free; + function Same_Net (L, R : Net) return Boolean + is + Linst : Instance; + Rinst : Instance; + begin + if L = R then + -- Obvious case. + return True; + end if; + + if Get_Width (L) /= Get_Width (R) then + -- Must have the same width. + return False; + end if; + + -- Handle extract. + Linst := Get_Net_Parent (L); + if Get_Id (Linst) /= Id_Extract then + return False; + end if; + Rinst := Get_Net_Parent (R); + if Get_Id (Rinst) /= Id_Extract then + return False; + end if; + return Get_Input_Net (Linst, 0) = Get_Input_Net (Rinst, 0) + and then Get_Param_Uns32 (Linst, 0) = Get_Param_Uns32 (Rinst, 0); + end Same_Net; + function Clog2 (W : Width) return Width is begin return Uns32 (Mutils.Clog2 (Uns64 (W))); diff --git a/src/synth/netlists-utils.ads b/src/synth/netlists-utils.ads index 6a29e0034..79838b614 100644 --- a/src/synth/netlists-utils.ads +++ b/src/synth/netlists-utils.ads @@ -74,6 +74,11 @@ package Netlists.Utils is -- disconnect and free it. procedure Disconnect_And_Free (I : Input); + -- Return true IFF L and R is the same net. + -- Either because L = R (obvious case) or because both are the same + -- selection of the same net. + function Same_Net (L, R : Net) return Boolean; + function Clog2 (W : Width) return Width; -- Used at many places. diff --git a/src/synth/synth-environment.adb b/src/synth/synth-environment.adb index 11c4b505d..0f5d8816e 100644 --- a/src/synth/synth-environment.adb +++ b/src/synth/synth-environment.adb @@ -1018,7 +1018,7 @@ package body Synth.Environment is -- Build mux. N1_Inst := Get_Net_Parent (N (1)); if Get_Id (N1_Inst) = Id_Mux2 - and then Get_Driver (Get_Mux2_I0 (N1_Inst)) = N (0) + and then Same_Net (Get_Driver (Get_Mux2_I0 (N1_Inst)), N (0)) then Res := Build_Mux2 (Ctxt, Build_Dyadic (Ctxt, Id_And, |