[llvm] [clang] [RISCV] Add sifive-p670 processor (PR #79015)

Michael Maitland via cfe-commits cfe-commits at lists.llvm.org
Mon Jan 22 11:08:54 PST 2024


https://github.com/michaelmaitland updated https://github.com/llvm/llvm-project/pull/79015

>From 639d404b3b8a8ca7e92160fa8512459be07e631f Mon Sep 17 00:00:00 2001
From: Michael Maitland <michaeltmaitland at gmail.com>
Date: Mon, 22 Jan 2024 07:53:55 -0800
Subject: [PATCH 1/3] [RISCV] Add sifive-p670 processor

This is an OOO core that has a vector unit. For more information see
https://www.sifive.com/cores/performance-p650-670.

This CPU prefers to not sink splat operands since it requires a s2V
transfer buffer to move scalars into buffers.

Scheduler model and other tuning will come in separate patches.
---
 clang/test/Driver/riscv-cpus.c                |  12 +-
 clang/test/Misc/target-invalid-cpu-note.c     |   4 +-
 llvm/lib/Target/RISCV/RISCVFeatures.td        |   7 +
 llvm/lib/Target/RISCV/RISCVISelLowering.cpp   |   8 +
 llvm/lib/Target/RISCV/RISCVProcessors.td      |  37 ++
 .../RISCV/rvv/dont-sink-splat-operands.ll     | 353 ++++++++++++++++++
 6 files changed, 418 insertions(+), 3 deletions(-)
 create mode 100644 llvm/test/CodeGen/RISCV/rvv/dont-sink-splat-operands.ll

diff --git a/clang/test/Driver/riscv-cpus.c b/clang/test/Driver/riscv-cpus.c
index d181755bb585070..666a3e2beabeb1e 100644
--- a/clang/test/Driver/riscv-cpus.c
+++ b/clang/test/Driver/riscv-cpus.c
@@ -241,7 +241,17 @@
 // MCPU-SIFIVE-P450-SAME: "-target-feature" "+zbb"
 // MCPU-SIFIVE-P450-SAME: "-target-feature" "+zbs"
 // MCPU-SIFIVE-P450-SAME: "-target-abi" "lp64d"
-//
+
+// RUN: %clang -target riscv64 -### -c %s 2>&1 -mcpu=sifive-p670 | FileCheck -check-prefix=MCPU-SIFIVE-P670 %s
+// MCPU-SIFIVE-P670: "-target-cpu" "sifive-p670"
+// MCPU-SIFIVE-P670-SAME: "-target-feature" "+m" "-target-feature" "+a" "-target-feature" "+f" "-target-feature" "+d"
+// MCPU-SIFIVE-P670-SAME: "-target-feature" "+c" "-target-feature" "+v" "-target-feature" "+zic64b" "-target-feature" "+zicbom" "-target-feature" "+zicbop" "-target-feature" "+zicboz" "-target-feature" "+ziccamoa" "-target-feature" "+ziccif" "-target-feature" "+zicclsm" "-target-feature" "+ziccrse" "-target-feature" "+zicsr" "-target-feature" "+zifencei" "-target-feature" "+zihintntl" "-target-feature" "+zihintpause" "-target-feature" "+zihpm" "-target-feature" "+za64rs" "-target-feature" "+zfhmin"
+// MCPU-SIFIVE-P670-SAME: "-target-feature" "+zba" "-target-feature" "+zbb" "-target-feature" "+zbs"
+// MCPU-SIFIVE-P670-SAME: "-target-feature" "+zvbb" "-target-feature" "+zvbc"
+// MCPU-SIFIVE-P670-SAME: "-target-feature" "+zve32f" "-target-feature" "+zve32x" "-target-feature" "+zve64d" "-target-feature" "+zve64f" "-target-feature" "+zve64x"
+// MCPU-SIFIVE-P670-SAME: "-target-feature" "+zvkg" "-target-feature" "+zvkn" "-target-feature" "+zvknc" "-target-feature" "+zvkned" "-target-feature" "+zvkng" "-target-feature" "+zvknhb" "-target-feature" "+zvks" "-target-feature" "+zvksc" "-target-feature" "+zvksed" "-target-feature" "+zvksg" "-target-feature" "+zvksh" "-target-feature" "+zvkt"
+// MCPU-SIFIVE-P670-SAME: "-target-abi" "lp64d"
+
 // Check failed cases
 
 // RUN: not %clang --target=riscv32 -### -c %s 2>&1 -mcpu=generic-rv321 | FileCheck -check-prefix=FAIL-MCPU-NAME %s
diff --git a/clang/test/Misc/target-invalid-cpu-note.c b/clang/test/Misc/target-invalid-cpu-note.c
index 48e9f05d9b03de2..84aed5c9c36fe47 100644
--- a/clang/test/Misc/target-invalid-cpu-note.c
+++ b/clang/test/Misc/target-invalid-cpu-note.c
@@ -85,7 +85,7 @@
 
 // RUN: not %clang_cc1 -triple riscv64 -target-cpu not-a-cpu -fsyntax-only %s 2>&1 | FileCheck %s --check-prefix RISCV64
 // RISCV64: error: unknown target CPU 'not-a-cpu'
-// RISCV64-NEXT: note: valid target CPU values are: generic-rv64, rocket-rv64, sifive-p450, sifive-s21, sifive-s51, sifive-s54, sifive-s76, sifive-u54, sifive-u74, sifive-x280, veyron-v1, xiangshan-nanhu{{$}}
+// RISCV64-NEXT: note: valid target CPU values are: generic-rv64, rocket-rv64, sifive-p450, sifive-p670, sifive-s21, sifive-s51, sifive-s54, sifive-s76, sifive-u54, sifive-u74, sifive-x280, veyron-v1, xiangshan-nanhu{{$}}
 
 // RUN: not %clang_cc1 -triple riscv32 -tune-cpu not-a-cpu -fsyntax-only %s 2>&1 | FileCheck %s --check-prefix TUNE-RISCV32
 // TUNE-RISCV32: error: unknown target CPU 'not-a-cpu'
@@ -93,4 +93,4 @@
 
 // RUN: not %clang_cc1 -triple riscv64 -tune-cpu not-a-cpu -fsyntax-only %s 2>&1 | FileCheck %s --check-prefix TUNE-RISCV64
 // TUNE-RISCV64: error: unknown target CPU 'not-a-cpu'
-// TUNE-RISCV64-NEXT: note: valid target CPU values are: generic-rv64, rocket-rv64, sifive-p450, sifive-s21, sifive-s51, sifive-s54, sifive-s76, sifive-u54, sifive-u74, sifive-x280, veyron-v1, xiangshan-nanhu, generic, rocket, sifive-7-series{{$}}
+// TUNE-RISCV64-NEXT: note: valid target CPU values are: generic-rv64, rocket-rv64, sifive-p450, sifive-p670, sifive-s21, sifive-s51, sifive-s54, sifive-s76, sifive-u54, sifive-u74, sifive-x280, veyron-v1, xiangshan-nanhu, generic, rocket, sifive-7-series{{$}}
diff --git a/llvm/lib/Target/RISCV/RISCVFeatures.td b/llvm/lib/Target/RISCV/RISCVFeatures.td
index cbb096ba20ae67b..04ee6d6d0547378 100644
--- a/llvm/lib/Target/RISCV/RISCVFeatures.td
+++ b/llvm/lib/Target/RISCV/RISCVFeatures.td
@@ -1082,6 +1082,13 @@ def TuneShortForwardBranchOpt
 def HasShortForwardBranchOpt : Predicate<"Subtarget->hasShortForwardBranchOpt()">;
 def NoShortForwardBranchOpt : Predicate<"!Subtarget->hasShortForwardBranchOpt()">;
 
+// P670 requires a S2V transfer buffer to move scalars into vectors.
+// FIXME: Forming .vx/.vf can reduce register pressure.
+def TuneDontSinkSplatOperands
+    : SubtargetFeature<"dont-sink-splat-operands", "DontSinkSplatOperands",
+                       "true", "Don't sink splat operands to enable .vx or .vf "
+                       "instructions">;
+
 def TuneConditionalCompressedMoveFusion
     : SubtargetFeature<"conditional-cmv-fusion", "HasConditionalCompressedMoveFusion",
                        "true", "Enable branch+c.mv fusion">;
diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
index b41e2f40dc72f01..6737f1c16238909 100644
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -2000,6 +2000,14 @@ bool RISCVTargetLowering::shouldSinkOperands(
   if (!I->getType()->isVectorTy() || !Subtarget.hasVInstructions())
     return false;
 
+  // Don't sink splat operands if the target prefers it. Some targets requires
+  // S2V transfer buffers and we can run out of them copying the same value
+  // repeatedly.
+  // FIXME: It could still be worth doing if it would improve vector register
+  // pressure and prevent a vector spill.
+  if (Subtarget.dontSinkSplatOperands())
+    return false;
+
   for (auto OpIdx : enumerate(I->operands())) {
     if (!canSplatOperand(I, OpIdx.index()))
       continue;
diff --git a/llvm/lib/Target/RISCV/RISCVProcessors.td b/llvm/lib/Target/RISCV/RISCVProcessors.td
index d1cd9ba1dd84d1b..c7425de99dc132c 100644
--- a/llvm/lib/Target/RISCV/RISCVProcessors.td
+++ b/llvm/lib/Target/RISCV/RISCVProcessors.td
@@ -237,6 +237,43 @@ def SIFIVE_P450 : RISCVProcessorModel<"sifive-p450", SiFiveP400Model,
                                        TuneLUIADDIFusion,
                                        TuneAUIPCADDIFusion]>;
 
+def SIFIVE_P670 : RISCVProcessorModel<"sifive-p670", NoSchedModel,
+                                      [Feature64Bit,
+                                       FeatureStdExtZifencei,
+                                       FeatureStdExtM,
+                                       FeatureStdExtA,
+                                       FeatureStdExtF,
+                                       FeatureStdExtD,
+                                       FeatureStdExtC,
+                                       FeatureStdExtZa64rs,
+                                       FeatureStdExtZic64b,
+                                       FeatureStdExtZicbop,
+                                       FeatureStdExtZicbom,
+                                       FeatureStdExtZicboz,
+                                       FeatureStdExtZiccamoa,
+                                       FeatureStdExtZiccif,
+                                       FeatureStdExtZicclsm,
+                                       FeatureStdExtZiccrse,
+                                       FeatureStdExtZihintntl,
+                                       FeatureStdExtZihintpause,
+                                       FeatureStdExtZihpm,
+                                       FeatureStdExtZba,
+                                       FeatureStdExtZbb,
+                                       FeatureStdExtZbs,
+                                       FeatureStdExtZfhmin,
+                                       FeatureStdExtV,
+                                       FeatureStdExtZvl128b,
+                                       FeatureStdExtZvbb,
+                                       FeatureStdExtZvknc,
+                                       FeatureStdExtZvkng,
+                                       FeatureStdExtZvksc,
+                                       FeatureStdExtZvksg,
+                                       FeatureFastUnalignedAccess],
+                                      [TuneNoDefaultUnroll,
+                                       TuneConditionalCompressedMoveFusion,
+                                       TuneLUIADDIFusion,
+                                       TuneDontSinkSplatOperands]>;
+
 def SYNTACORE_SCR1_BASE : RISCVProcessorModel<"syntacore-scr1-base",
                                               SyntacoreSCR1Model,
                                               [Feature32Bit,
diff --git a/llvm/test/CodeGen/RISCV/rvv/dont-sink-splat-operands.ll b/llvm/test/CodeGen/RISCV/rvv/dont-sink-splat-operands.ll
new file mode 100644
index 000000000000000..88eac06294240c4
--- /dev/null
+++ b/llvm/test/CodeGen/RISCV/rvv/dont-sink-splat-operands.ll
@@ -0,0 +1,353 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc < %s -mtriple=riscv64 -mattr=+m,+v,+f -target-abi=lp64f \
+; RUN:   -mattr=+dont-sink-splat-operands -riscv-v-vector-bits-min=128 | FileCheck %s
+
+; Test that we don't sink splat operands when compiling with dont-sink-splat-operands.
+; Each scalar register access requires a S2V transfer buffer entry. Using too many
+; limits performance.
+; FIXME: This is potentially bad for register pressure. Need a better heuristic.
+
+define void @sink_splat_add(i32* nocapture %a, i32 signext %x) {
+; CHECK-LABEL: sink_splat_add:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    vsetivli zero, 4, e32, m1, ta, ma
+; CHECK-NEXT:    vmv.v.x v8, a1
+; CHECK-NEXT:    li a1, 1024
+; CHECK-NEXT:  .LBB0_1: # %vector.body
+; CHECK-NEXT:    # =>This Inner Loop Header: Depth=1
+; CHECK-NEXT:    vle32.v v9, (a0)
+; CHECK-NEXT:    vadd.vv v9, v9, v8
+; CHECK-NEXT:    vse32.v v9, (a0)
+; CHECK-NEXT:    addi a1, a1, -4
+; CHECK-NEXT:    addi a0, a0, 16
+; CHECK-NEXT:    bnez a1, .LBB0_1
+; CHECK-NEXT:  # %bb.2: # %for.cond.cleanup
+; CHECK-NEXT:    ret
+entry:
+  %broadcast.splatinsert = insertelement <4 x i32> poison, i32 %x, i32 0
+  %broadcast.splat = shufflevector <4 x i32> %broadcast.splatinsert, <4 x i32> poison, <4 x i32> zeroinitializer
+  br label %vector.body
+
+vector.body:                                      ; preds = %vector.body, %entry
+  %index = phi i64 [ 0, %entry ], [ %index.next, %vector.body ]
+  %0 = getelementptr inbounds i32, i32* %a, i64 %index
+  %1 = bitcast i32* %0 to <4 x i32>*
+  %wide.load = load <4 x i32>, <4 x i32>* %1, align 4
+  %2 = add <4 x i32> %wide.load, %broadcast.splat
+  %3 = bitcast i32* %0 to <4 x i32>*
+  store <4 x i32> %2, <4 x i32>* %3, align 4
+  %index.next = add nuw i64 %index, 4
+  %4 = icmp eq i64 %index.next, 1024
+  br i1 %4, label %for.cond.cleanup, label %vector.body
+
+for.cond.cleanup:                                 ; preds = %vector.body
+  ret void
+}
+
+declare i64 @llvm.vscale.i64()
+
+define void @sink_splat_add_scalable(i32* nocapture %a, i32 signext %x) {
+; CHECK-LABEL: sink_splat_add_scalable:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    csrr a5, vlenb
+; CHECK-NEXT:    srli a3, a5, 1
+; CHECK-NEXT:    li a2, 1024
+; CHECK-NEXT:    bgeu a2, a3, .LBB1_2
+; CHECK-NEXT:  # %bb.1:
+; CHECK-NEXT:    li a2, 0
+; CHECK-NEXT:    j .LBB1_5
+; CHECK-NEXT:  .LBB1_2: # %vector.ph
+; CHECK-NEXT:    addi a2, a3, -1
+; CHECK-NEXT:    andi a4, a2, 1024
+; CHECK-NEXT:    xori a2, a4, 1024
+; CHECK-NEXT:    vsetvli a6, zero, e32, m2, ta, ma
+; CHECK-NEXT:    vmv.v.x v8, a1
+; CHECK-NEXT:    slli a5, a5, 1
+; CHECK-NEXT:    mv a6, a0
+; CHECK-NEXT:    mv a7, a2
+; CHECK-NEXT:  .LBB1_3: # %vector.body
+; CHECK-NEXT:    # =>This Inner Loop Header: Depth=1
+; CHECK-NEXT:    vl2re32.v v10, (a6)
+; CHECK-NEXT:    vadd.vv v10, v10, v8
+; CHECK-NEXT:    vs2r.v v10, (a6)
+; CHECK-NEXT:    sub a7, a7, a3
+; CHECK-NEXT:    add a6, a6, a5
+; CHECK-NEXT:    bnez a7, .LBB1_3
+; CHECK-NEXT:  # %bb.4: # %middle.block
+; CHECK-NEXT:    beqz a4, .LBB1_7
+; CHECK-NEXT:  .LBB1_5: # %for.body.preheader
+; CHECK-NEXT:    addi a3, a2, -1024
+; CHECK-NEXT:    slli a2, a2, 2
+; CHECK-NEXT:    add a0, a0, a2
+; CHECK-NEXT:  .LBB1_6: # %for.body
+; CHECK-NEXT:    # =>This Inner Loop Header: Depth=1
+; CHECK-NEXT:    lw a2, 0(a0)
+; CHECK-NEXT:    add a2, a2, a1
+; CHECK-NEXT:    sw a2, 0(a0)
+; CHECK-NEXT:    addi a3, a3, 1
+; CHECK-NEXT:    addi a0, a0, 4
+; CHECK-NEXT:    bnez a3, .LBB1_6
+; CHECK-NEXT:  .LBB1_7: # %for.cond.cleanup
+; CHECK-NEXT:    ret
+entry:
+  %0 = call i64 @llvm.vscale.i64()
+  %1 = shl i64 %0, 2
+  %min.iters.check = icmp ugt i64 %1, 1024
+  br i1 %min.iters.check, label %for.body.preheader, label %vector.ph
+
+vector.ph:                                        ; preds = %entry
+  %2 = call i64 @llvm.vscale.i64()
+  %3 = shl i64 %2, 2
+  %n.mod.vf = urem i64 1024, %3
+  %n.vec = sub nsw i64 1024, %n.mod.vf
+  %broadcast.splatinsert = insertelement <vscale x 4 x i32> poison, i32 %x, i32 0
+  %broadcast.splat = shufflevector <vscale x 4 x i32> %broadcast.splatinsert, <vscale x 4 x i32> poison, <vscale x 4 x i32> zeroinitializer
+  %4 = call i64 @llvm.vscale.i64()
+  %5 = shl i64 %4, 2
+  br label %vector.body
+
+vector.body:                                      ; preds = %vector.body, %vector.ph
+  %index = phi i64 [ 0, %vector.ph ], [ %index.next, %vector.body ]
+  %6 = getelementptr inbounds i32, i32* %a, i64 %index
+  %7 = bitcast i32* %6 to <vscale x 4 x i32>*
+  %wide.load = load <vscale x 4 x i32>, <vscale x 4 x i32>* %7, align 4
+  %8 = add <vscale x 4 x i32> %wide.load, %broadcast.splat
+  %9 = bitcast i32* %6 to <vscale x 4 x i32>*
+  store <vscale x 4 x i32> %8, <vscale x 4 x i32>* %9, align 4
+  %index.next = add nuw i64 %index, %5
+  %10 = icmp eq i64 %index.next, %n.vec
+  br i1 %10, label %middle.block, label %vector.body
+
+middle.block:                                     ; preds = %vector.body
+  %cmp.n = icmp eq i64 %n.mod.vf, 0
+  br i1 %cmp.n, label %for.cond.cleanup, label %for.body.preheader
+
+for.body.preheader:                               ; preds = %entry, %middle.block
+  %indvars.iv.ph = phi i64 [ 0, %entry ], [ %n.vec, %middle.block ]
+  br label %for.body
+
+for.cond.cleanup:                                 ; preds = %for.body, %middle.block
+  ret void
+
+for.body:                                         ; preds = %for.body.preheader, %for.body
+  %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ %indvars.iv.ph, %for.body.preheader ]
+  %arrayidx = getelementptr inbounds i32, i32* %a, i64 %indvars.iv
+  %11 = load i32, i32* %arrayidx, align 4
+  %add = add i32 %11, %x
+  store i32 %add, i32* %arrayidx, align 4
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %cmp.not = icmp eq i64 %indvars.iv.next, 1024
+  br i1 %cmp.not, label %for.cond.cleanup, label %for.body
+}
+
+declare <4 x i32> @llvm.vp.add.v4i32(<4 x i32>, <4 x i32>, <4 x i1>, i32)
+
+define void @sink_splat_vp_add(i32* nocapture %a, i32 signext %x, <4 x i1> %m, i32 zeroext %vl) {
+; CHECK-LABEL: sink_splat_vp_add:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    vsetivli zero, 4, e32, m1, ta, ma
+; CHECK-NEXT:    vmv.v.x v8, a1
+; CHECK-NEXT:    li a1, 1024
+; CHECK-NEXT:  .LBB2_1: # %vector.body
+; CHECK-NEXT:    # =>This Inner Loop Header: Depth=1
+; CHECK-NEXT:    vle32.v v9, (a0)
+; CHECK-NEXT:    vsetvli zero, a2, e32, m1, ta, ma
+; CHECK-NEXT:    vadd.vv v9, v9, v8, v0.t
+; CHECK-NEXT:    vsetivli zero, 4, e32, m1, ta, ma
+; CHECK-NEXT:    vse32.v v9, (a0)
+; CHECK-NEXT:    addi a1, a1, -4
+; CHECK-NEXT:    addi a0, a0, 16
+; CHECK-NEXT:    bnez a1, .LBB2_1
+; CHECK-NEXT:  # %bb.2: # %for.cond.cleanup
+; CHECK-NEXT:    ret
+entry:
+  %broadcast.splatinsert = insertelement <4 x i32> poison, i32 %x, i32 0
+  %broadcast.splat = shufflevector <4 x i32> %broadcast.splatinsert, <4 x i32> poison, <4 x i32> zeroinitializer
+  br label %vector.body
+
+vector.body:                                      ; preds = %vector.body, %entry
+  %index = phi i64 [ 0, %entry ], [ %index.next, %vector.body ]
+  %0 = getelementptr inbounds i32, i32* %a, i64 %index
+  %1 = bitcast i32* %0 to <4 x i32>*
+  %wide.load = load <4 x i32>, <4 x i32>* %1, align 4
+  %2 = call <4 x i32> @llvm.vp.add.v4i32(<4 x i32> %wide.load, <4 x i32> %broadcast.splat, <4 x i1> %m, i32 %vl)
+  %3 = bitcast i32* %0 to <4 x i32>*
+  store <4 x i32> %2, <4 x i32>* %3, align 4
+  %index.next = add nuw i64 %index, 4
+  %4 = icmp eq i64 %index.next, 1024
+  br i1 %4, label %for.cond.cleanup, label %vector.body
+
+for.cond.cleanup:                                 ; preds = %vector.body
+  ret void
+}
+
+define void @sink_splat_fadd(float* nocapture %a, float %x) {
+; CHECK-LABEL: sink_splat_fadd:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    vsetivli zero, 4, e32, m1, ta, ma
+; CHECK-NEXT:    vfmv.v.f v8, fa0
+; CHECK-NEXT:    li a1, 1024
+; CHECK-NEXT:  .LBB3_1: # %vector.body
+; CHECK-NEXT:    # =>This Inner Loop Header: Depth=1
+; CHECK-NEXT:    vle32.v v9, (a0)
+; CHECK-NEXT:    vfadd.vv v9, v9, v8
+; CHECK-NEXT:    vse32.v v9, (a0)
+; CHECK-NEXT:    addi a1, a1, -4
+; CHECK-NEXT:    addi a0, a0, 16
+; CHECK-NEXT:    bnez a1, .LBB3_1
+; CHECK-NEXT:  # %bb.2: # %for.cond.cleanup
+; CHECK-NEXT:    ret
+entry:
+  %broadcast.splatinsert = insertelement <4 x float> poison, float %x, i32 0
+  %broadcast.splat = shufflevector <4 x float> %broadcast.splatinsert, <4 x float> poison, <4 x i32> zeroinitializer
+  br label %vector.body
+
+vector.body:                                      ; preds = %vector.body, %entry
+  %index = phi i64 [ 0, %entry ], [ %index.next, %vector.body ]
+  %0 = getelementptr inbounds float, float* %a, i64 %index
+  %1 = bitcast float* %0 to <4 x float>*
+  %wide.load = load <4 x float>, <4 x float>* %1, align 4
+  %2 = fadd <4 x float> %wide.load, %broadcast.splat
+  %3 = bitcast float* %0 to <4 x float>*
+  store <4 x float> %2, <4 x float>* %3, align 4
+  %index.next = add nuw i64 %index, 4
+  %4 = icmp eq i64 %index.next, 1024
+  br i1 %4, label %for.cond.cleanup, label %vector.body
+
+for.cond.cleanup:                                 ; preds = %vector.body
+  ret void
+}
+
+define void @sink_splat_fadd_scalable(float* nocapture %a, float %x) {
+; CHECK-LABEL: sink_splat_fadd_scalable:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    csrr a1, vlenb
+; CHECK-NEXT:    srli a3, a1, 2
+; CHECK-NEXT:    li a2, 1024
+; CHECK-NEXT:    bgeu a2, a3, .LBB4_2
+; CHECK-NEXT:  # %bb.1:
+; CHECK-NEXT:    li a2, 0
+; CHECK-NEXT:    j .LBB4_5
+; CHECK-NEXT:  .LBB4_2: # %vector.ph
+; CHECK-NEXT:    addi a2, a3, -1
+; CHECK-NEXT:    andi a4, a2, 1024
+; CHECK-NEXT:    xori a2, a4, 1024
+; CHECK-NEXT:    vsetvli a5, zero, e32, m1, ta, ma
+; CHECK-NEXT:    vfmv.v.f v8, fa0
+; CHECK-NEXT:    mv a5, a0
+; CHECK-NEXT:    mv a6, a2
+; CHECK-NEXT:  .LBB4_3: # %vector.body
+; CHECK-NEXT:    # =>This Inner Loop Header: Depth=1
+; CHECK-NEXT:    vl1re32.v v9, (a5)
+; CHECK-NEXT:    vfadd.vv v9, v9, v8
+; CHECK-NEXT:    vs1r.v v9, (a5)
+; CHECK-NEXT:    sub a6, a6, a3
+; CHECK-NEXT:    add a5, a5, a1
+; CHECK-NEXT:    bnez a6, .LBB4_3
+; CHECK-NEXT:  # %bb.4: # %middle.block
+; CHECK-NEXT:    beqz a4, .LBB4_7
+; CHECK-NEXT:  .LBB4_5: # %for.body.preheader
+; CHECK-NEXT:    addi a1, a2, -1024
+; CHECK-NEXT:    slli a2, a2, 2
+; CHECK-NEXT:    add a0, a0, a2
+; CHECK-NEXT:  .LBB4_6: # %for.body
+; CHECK-NEXT:    # =>This Inner Loop Header: Depth=1
+; CHECK-NEXT:    flw fa5, 0(a0)
+; CHECK-NEXT:    fadd.s fa5, fa5, fa0
+; CHECK-NEXT:    fsw fa5, 0(a0)
+; CHECK-NEXT:    addi a1, a1, 1
+; CHECK-NEXT:    addi a0, a0, 4
+; CHECK-NEXT:    bnez a1, .LBB4_6
+; CHECK-NEXT:  .LBB4_7: # %for.cond.cleanup
+; CHECK-NEXT:    ret
+entry:
+  %0 = call i64 @llvm.vscale.i64()
+  %1 = shl i64 %0, 1
+  %min.iters.check = icmp ugt i64 %1, 1024
+  br i1 %min.iters.check, label %for.body.preheader, label %vector.ph
+
+vector.ph:                                        ; preds = %entry
+  %2 = call i64 @llvm.vscale.i64()
+  %3 = shl i64 %2, 1
+  %n.mod.vf = urem i64 1024, %3
+  %n.vec = sub nsw i64 1024, %n.mod.vf
+  %broadcast.splatinsert = insertelement <vscale x 2 x float> poison, float %x, i32 0
+  %broadcast.splat = shufflevector <vscale x 2 x float> %broadcast.splatinsert, <vscale x 2 x float> poison, <vscale x 2 x i32> zeroinitializer
+  %4 = call i64 @llvm.vscale.i64()
+  %5 = shl i64 %4, 1
+  br label %vector.body
+
+vector.body:                                      ; preds = %vector.body, %vector.ph
+  %index = phi i64 [ 0, %vector.ph ], [ %index.next, %vector.body ]
+  %6 = getelementptr inbounds float, float* %a, i64 %index
+  %7 = bitcast float* %6 to <vscale x 2 x float>*
+  %wide.load = load <vscale x 2 x float>, <vscale x 2 x float>* %7, align 4
+  %8 = fadd <vscale x 2 x float> %wide.load, %broadcast.splat
+  %9 = bitcast float* %6 to <vscale x 2 x float>*
+  store <vscale x 2 x float> %8, <vscale x 2 x float>* %9, align 4
+  %index.next = add nuw i64 %index, %5
+  %10 = icmp eq i64 %index.next, %n.vec
+  br i1 %10, label %middle.block, label %vector.body
+
+middle.block:                                     ; preds = %vector.body
+  %cmp.n = icmp eq i64 %n.mod.vf, 0
+  br i1 %cmp.n, label %for.cond.cleanup, label %for.body.preheader
+
+for.body.preheader:                               ; preds = %entry, %middle.block
+  %indvars.iv.ph = phi i64 [ 0, %entry ], [ %n.vec, %middle.block ]
+  br label %for.body
+
+for.cond.cleanup:                                 ; preds = %for.body, %middle.block
+  ret void
+
+for.body:                                         ; preds = %for.body.preheader, %for.body
+  %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ %indvars.iv.ph, %for.body.preheader ]
+  %arrayidx = getelementptr inbounds float, float* %a, i64 %indvars.iv
+  %11 = load float, float* %arrayidx, align 4
+  %mul = fadd float %11, %x
+  store float %mul, float* %arrayidx, align 4
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %cmp.not = icmp eq i64 %indvars.iv.next, 1024
+  br i1 %cmp.not, label %for.cond.cleanup, label %for.body
+}
+
+declare <4 x float> @llvm.vp.fadd.v4i32(<4 x float>, <4 x float>, <4 x i1>, i32)
+
+define void @sink_splat_vp_fadd(float* nocapture %a, float %x, <4 x i1> %m, i32 zeroext %vl) {
+; CHECK-LABEL: sink_splat_vp_fadd:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    vsetivli zero, 4, e32, m1, ta, ma
+; CHECK-NEXT:    vfmv.v.f v8, fa0
+; CHECK-NEXT:    li a2, 1024
+; CHECK-NEXT:  .LBB5_1: # %vector.body
+; CHECK-NEXT:    # =>This Inner Loop Header: Depth=1
+; CHECK-NEXT:    vle32.v v9, (a0)
+; CHECK-NEXT:    vsetvli zero, a1, e32, m1, ta, ma
+; CHECK-NEXT:    vfadd.vv v9, v9, v8, v0.t
+; CHECK-NEXT:    vsetivli zero, 4, e32, m1, ta, ma
+; CHECK-NEXT:    vse32.v v9, (a0)
+; CHECK-NEXT:    addi a2, a2, -4
+; CHECK-NEXT:    addi a0, a0, 16
+; CHECK-NEXT:    bnez a2, .LBB5_1
+; CHECK-NEXT:  # %bb.2: # %for.cond.cleanup
+; CHECK-NEXT:    ret
+entry:
+  %broadcast.splatinsert = insertelement <4 x float> poison, float %x, i32 0
+  %broadcast.splat = shufflevector <4 x float> %broadcast.splatinsert, <4 x float> poison, <4 x i32> zeroinitializer
+  br label %vector.body
+
+vector.body:                                      ; preds = %vector.body, %entry
+  %index = phi i64 [ 0, %entry ], [ %index.next, %vector.body ]
+  %0 = getelementptr inbounds float, float* %a, i64 %index
+  %1 = bitcast float* %0 to <4 x float>*
+  %wide.load = load <4 x float>, <4 x float>* %1, align 4
+  %2 = call <4 x float> @llvm.vp.fadd.v4i32(<4 x float> %wide.load, <4 x float> %broadcast.splat, <4 x i1> %m, i32 %vl)
+  %3 = bitcast float* %0 to <4 x float>*
+  store <4 x float> %2, <4 x float>* %3, align 4
+  %index.next = add nuw i64 %index, 4
+  %4 = icmp eq i64 %index.next, 1024
+  br i1 %4, label %for.cond.cleanup, label %vector.body
+
+for.cond.cleanup:                                 ; preds = %vector.body
+  ret void
+}

>From d6f7c9fb615bd067eb3cd7e47c0caa3fe06202c2 Mon Sep 17 00:00:00 2001
From: Michael Maitland <michaeltmaitland at gmail.com>
Date: Mon, 22 Jan 2024 09:29:03 -0800
Subject: [PATCH 2/3] !fixup add auipc fusion

---
 llvm/lib/Target/RISCV/RISCVProcessors.td | 1 +
 1 file changed, 1 insertion(+)

diff --git a/llvm/lib/Target/RISCV/RISCVProcessors.td b/llvm/lib/Target/RISCV/RISCVProcessors.td
index c7425de99dc132c..c5dc2a6e064d752 100644
--- a/llvm/lib/Target/RISCV/RISCVProcessors.td
+++ b/llvm/lib/Target/RISCV/RISCVProcessors.td
@@ -272,6 +272,7 @@ def SIFIVE_P670 : RISCVProcessorModel<"sifive-p670", NoSchedModel,
                                       [TuneNoDefaultUnroll,
                                        TuneConditionalCompressedMoveFusion,
                                        TuneLUIADDIFusion,
+                                       TuneAUIPCADDIFusion,
                                        TuneDontSinkSplatOperands]>;
 
 def SYNTACORE_SCR1_BASE : RISCVProcessorModel<"syntacore-scr1-base",

>From 5f812ad9f65ebeb766b2d63e23f3d0132bfdb8a3 Mon Sep 17 00:00:00 2001
From: Michael Maitland <michaeltmaitland at gmail.com>
Date: Mon, 22 Jan 2024 11:08:37 -0800
Subject: [PATCH 3/3] !fixup update docs/ReleaseNotes.rst

---
 llvm/docs/ReleaseNotes.rst | 1 +
 1 file changed, 1 insertion(+)

diff --git a/llvm/docs/ReleaseNotes.rst b/llvm/docs/ReleaseNotes.rst
index c17c834c8081b8a..8956ded9e4b0f64 100644
--- a/llvm/docs/ReleaseNotes.rst
+++ b/llvm/docs/ReleaseNotes.rst
@@ -165,6 +165,7 @@ Changes to the RISC-V Backend
   and Zic64b extensions which were introduced as a part of the RISC-V Profiles
   specification.
 * The Smepmp 1.0 extension is now supported.
+* ``-mcpu=sifive-p670`` was added.
 
 Changes to the WebAssembly Backend
 ----------------------------------



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