From 9ab964e840e44940a57b47a921b0fe97319d1791 Mon Sep 17 00:00:00 2001
From: Michael Maitland <michaeltmaitland@gmail.com>
Date: Thu, 22 Jun 2023 10:19:04 -0700
Subject: [PATCH] Revert "[RISCV] Improve SiFive7 for reductions and ordered
 reductions"

This reverts commit 208fc34c65d648e869d7d3ba0dfcbca90942cda0.

Reverting because build failure.
---
 llvm/lib/Target/RISCV/RISCVSchedSiFive7.td | 95 +++---------------------------
 1 file changed, 8 insertions(+), 87 deletions(-)

diff --git a/llvm/lib/Target/RISCV/RISCVSchedSiFive7.td b/llvm/lib/Target/RISCV/RISCVSchedSiFive7.td
index ee85486..78a1e84 100644
--- a/llvm/lib/Target/RISCV/RISCVSchedSiFive7.td
+++ b/llvm/lib/Target/RISCV/RISCVSchedSiFive7.td
@@ -160,44 +160,6 @@ class SiFive7GetDivOrSqrtFactor<int sew> {
   );
 }
 
-/// Cycles for reductions take approximately VL*SEW/DLEN + 5(4 + log(DLEN/SEW))
-/// cycles.
-class SiFive7GetReductionCycles<string mx, int sew> {
-  // VLUpperBound*SEW/DLEN is equivalent to 2*LMUL since
-  // VLUpperBound=(VLEN*LMUL)/SEW.
-  defvar VLEN = 512;
-  defvar DLEN = !div(VLEN, 2);
-  defvar TwoTimesLMUL = !cond(
-    !eq(mx, "M1") : 2,
-    !eq(mx, "M2") : 4,
-    !eq(mx, "M4") : 8,
-    !eq(mx, "M8") : 16,
-    !eq(mx, "MF2") : 1,
-    !eq(mx, "MF4") : 1,
-    !eq(mx, "MF8") : 1
-  );
-  int c = !add(
-    !div(TwoTimesLMUL, DLEN),
-    !mul(5, !add(4, !logtwo(!div(DLEN, sew))))
-  );
-}
-
-/// Cycles for ordered reductions take approximatley 5*VL cycles
-class SiFive7GetOrderedReductionCycles<string mx, int sew> {
-  defvar VLEN = 512;
-  // (VLEN * LMUL) / SEW
-  defvar VLUpperBound  = !cond(
-    !eq(mx, "M1") : !div(VLEN, sew),
-    !eq(mx, "M2") : !div(!mul(VLEN, 2), sew),
-    !eq(mx, "M4") : !div(!mul(VLEN, 4), sew),
-    !eq(mx, "M8") : !div(!mul(VLEN, 8), sew),
-    !eq(mx, "MF2") : !div(!div(VLEN, 2), sew),
-    !eq(mx, "MF4") : !div(!div(VLEN, 4), sew),
-    !eq(mx, "MF8") : !div(!div(VLEN, 8), sew),
-  );
-  int c = !mul(5, VLUpperBound);
-}
-
 // SiFive7 machine model for scheduling and other instruction cost heuristics.
 def SiFive7Model : SchedMachineModel {
   let MicroOpBufferSize = 0; // Explicitly set to zero since SiFive7 is in-order.
@@ -768,55 +730,14 @@ foreach mx = SchedMxListFW in {
 }
 
 // 14. Vector Reduction Operations
-foreach mx = SchedMxList in {
-  foreach sew = SchedSEWSet<mx>.val in {
-    defvar Cycles = SiFive7GetReductionCycles<mx, sew>.c;
-    defvar IsWorstCase = SiFive7IsWorstCaseMXSEW<mx, sew, SchedMxList>.c;
-    let Latency = Cycles, ResourceCycles = [Cycles] in
-    defm "" : LMULSEWWriteResMXSEW<"WriteVIRedV_From", [SiFive7VA],
-                                   mx, sew, IsWorstCase>;
-  }
-}
-
-foreach mx = SchedMxListWRed in {
-  foreach sew = SchedSEWSet<mx, 1>.val in {
-    defvar Cycles = SiFive7GetReductionCycles<mx, sew>.c;
-    defvar IsWorstCase = SiFive7IsWorstCaseMXSEW<mx, sew, SchedMxListWRed>.c;
-    let Latency = Cycles, ResourceCycles = [Cycles] in
-    defm "" : LMULSEWWriteResMXSEW<"WriteVIWRedV_From", [SiFive7VA],
-                                   mx, sew, IsWorstCase>;
-  }
-}
-
-foreach mx = SchedMxListF in {
-  foreach sew = SchedSEWSetF<mx>.val in {
-    defvar RedCycles = SiFive7GetReductionCycles<mx, sew>.c;
-    defvar IsWorstCase = SiFive7IsWorstCaseMXSEW<mx, sew, SchedMxListF, 1>.c;
-    let Latency = RedCycles, ResourceCycles = [RedCycles] in {
-      defm "" : LMULSEWWriteResMXSEW<"WriteVFRedV_From", [SiFive7VA],
-                                     mx, sew, IsWorstCase>;
-      defm "" : LMULSEWWriteResMXSEW<"WriteVFRedMinMaxV_From", [SiFive7VA],
-                                     mx, sew, IsWorstCase>;
-    }
-    defvar OrdRedCycles = SiFive7GetOrderedReductionCycles<mx, sew>.c;
-    let Latency = OrdRedCycles, ResourceCycles = [OrdRedCycles] in
-    defm "" : LMULSEWWriteResMXSEW<"WriteVFRedOV_From", [SiFive7VA],
-                                   mx, sew, IsWorstCase>;
-  }
-}
-
-foreach mx = SchedMxListFWRed in {
-  foreach sew = SchedSEWSetF<mx, 1>.val in {
-    defvar RedCycles = SiFive7GetReductionCycles<mx, sew>.c;
-    defvar IsWorstCase = SiFive7IsWorstCaseMXSEW<mx, sew, SchedMxListFWRed, 1>.c;
-    let Latency = RedCycles, ResourceCycles = [RedCycles] in
-    defm "" : LMULSEWWriteResMXSEW<"WriteVFWRedV_From", [SiFive7VA],
-                                   mx, sew, IsWorstCase>;
-    defvar OrdRedCycles = SiFive7GetOrderedReductionCycles<mx, sew>.c;
-    let Latency = OrdRedCycles, ResourceCycles = [OrdRedCycles] in
-    defm "" : LMULSEWWriteResMXSEW<"WriteVFWRedOV_From", [SiFive7VA],
-                                   mx, sew, IsWorstCase>;
-  }
+let Latency = 32 in {
+defm "" : LMULSEWWriteRes<"WriteVIRedV_From", [SiFive7VA]>;
+defm "" : LMULSEWWriteRes<"WriteVIWRedV_From", [SiFive7VA]>;
+defm "" : LMULSEWWriteRes<"WriteVFRedV_From", [SiFive7VA]>;
+defm "" : LMULSEWWriteRes<"WriteVFRedOV_From", [SiFive7VA]>;
+defm "" : LMULSEWWriteResF<"WriteVFRedMinMaxV_From", [SiFive7VA]>;
+defm "" : LMULSEWWriteResFWRed<"WriteVFWRedV_From", [SiFive7VA]>;
+defm "" : LMULSEWWriteResFWRed<"WriteVFWRedOV_From", [SiFive7VA]>;
 }
 
 // 15. Vector Mask Instructions
-- 
2.7.4