[clang] [llvm] [RISCV] Remove Zicntr from sifive-p450/p470/p670. (PR #161444)

Craig Topper via llvm-commits llvm-commits at lists.llvm.org
Tue Sep 30 13:50:06 PDT 2025


https://github.com/topperc created https://github.com/llvm/llvm-project/pull/161444

These cores don't implement the `time` CSR. They require SBI to trap and emulate it which is allowed by RVA20U.

>From 257dc5f4b78600b0be2adf5de3cdb7fe7fbdf452 Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper at sifive.com>
Date: Tue, 30 Sep 2025 13:40:24 -0700
Subject: [PATCH] [RISCV] Remove Zicntr from sifive-p450/p470/p670.

These cores don't implement the `time` CSR. They require SBI to
trap and emulate it which is allowed by RVA20U.
---
 clang/test/Driver/riscv-cpus.c           |  3 -
 llvm/lib/Target/RISCV/RISCVProcessors.td | 81 +++++++++++++++++++++---
 2 files changed, 72 insertions(+), 12 deletions(-)

diff --git a/clang/test/Driver/riscv-cpus.c b/clang/test/Driver/riscv-cpus.c
index cd92adc64a7d6..5d5fdd72baedb 100644
--- a/clang/test/Driver/riscv-cpus.c
+++ b/clang/test/Driver/riscv-cpus.c
@@ -462,7 +462,6 @@
 // MCPU-SIFIVE-P450-SAME: "-target-feature" "+ziccif"
 // MCPU-SIFIVE-P450-SAME: "-target-feature" "+zicclsm"
 // MCPU-SIFIVE-P450-SAME: "-target-feature" "+ziccrse"
-// MCPU-SIFIVE-P450-SAME: "-target-feature" "+zicntr"
 // MCPU-SIFIVE-P450-SAME: "-target-feature" "+zicsr"
 // MCPU-SIFIVE-P450-SAME: "-target-feature" "+zifencei"
 // MCPU-SIFIVE-P450-SAME: "-target-feature" "+zihintntl"
@@ -492,7 +491,6 @@
 // MCPU-SIFIVE-P470-SAME: "-target-feature" "+ziccif"
 // MCPU-SIFIVE-P470-SAME: "-target-feature" "+zicclsm"
 // MCPU-SIFIVE-P470-SAME: "-target-feature" "+ziccrse"
-// MCPU-SIFIVE-P470-SAME: "-target-feature" "+zicntr"
 // MCPU-SIFIVE-P470-SAME: "-target-feature" "+zicsr"
 // MCPU-SIFIVE-P470-SAME: "-target-feature" "+zifencei"
 // MCPU-SIFIVE-P470-SAME: "-target-feature" "+zihintntl"
@@ -555,7 +553,6 @@
 // MCPU-SIFIVE-P670-SAME: "-target-feature" "+ziccif"
 // MCPU-SIFIVE-P670-SAME: "-target-feature" "+zicclsm"
 // MCPU-SIFIVE-P670-SAME: "-target-feature" "+ziccrse"
-// MCPU-SIFIVE-P670-SAME: "-target-feature" "+zicntr"
 // MCPU-SIFIVE-P670-SAME: "-target-feature" "+zicsr"
 // MCPU-SIFIVE-P670-SAME: "-target-feature" "+zifencei"
 // MCPU-SIFIVE-P670-SAME: "-target-feature" "+zihintntl"
diff --git a/llvm/lib/Target/RISCV/RISCVProcessors.td b/llvm/lib/Target/RISCV/RISCVProcessors.td
index 95f8a8789fa6c..17a794867be9e 100644
--- a/llvm/lib/Target/RISCV/RISCVProcessors.td
+++ b/llvm/lib/Target/RISCV/RISCVProcessors.td
@@ -347,16 +347,58 @@ defvar SiFiveP400TuneFeatures = [TuneNoDefaultUnroll,
                                  TunePostRAScheduler];
 
 def SIFIVE_P450 : RISCVProcessorModel<"sifive-p450", SiFiveP400Model,
-                                      !listconcat(RVA22U64Features,
-                                      [FeatureStdExtZifencei,
+                                      [Feature64Bit,
+                                       FeatureStdExtI,
+                                       FeatureStdExtM,
+                                       FeatureStdExtA,
+                                       FeatureStdExtF,
+                                       FeatureStdExtD,
+                                       FeatureStdExtC,
+                                       FeatureStdExtZicsr,
+                                       FeatureStdExtZiccif,
+                                       FeatureStdExtZiccrse,
+                                       FeatureStdExtZiccamoa,
+                                       FeatureStdExtZicclsm,
+                                       FeatureStdExtZa64rs,
+                                       FeatureStdExtZihpm,
+                                       FeatureStdExtZihintpause,
+                                       FeatureStdExtB,
+                                       FeatureStdExtZic64b,
+                                       FeatureStdExtZicbom,
+                                       FeatureStdExtZicbop,
+                                       FeatureStdExtZicboz,
+                                       FeatureStdExtZfhmin,
+                                       FeatureStdExtZkt,
+                                       FeatureStdExtZifencei,
                                        FeatureStdExtZihintntl,
                                        FeatureUnalignedScalarMem,
-                                       FeatureUnalignedVectorMem]),
+                                       FeatureUnalignedVectorMem],
                                       SiFiveP400TuneFeatures>;
 
 def SIFIVE_P470 : RISCVProcessorModel<"sifive-p470", SiFiveP400Model,
-                                      !listconcat(RVA22U64Features,
-                                      [FeatureStdExtV,
+                                      [Feature64Bit,
+                                       FeatureStdExtI,
+                                       FeatureStdExtM,
+                                       FeatureStdExtA,
+                                       FeatureStdExtF,
+                                       FeatureStdExtD,
+                                       FeatureStdExtC,
+                                       FeatureStdExtZicsr,
+                                       FeatureStdExtZiccif,
+                                       FeatureStdExtZiccrse,
+                                       FeatureStdExtZiccamoa,
+                                       FeatureStdExtZicclsm,
+                                       FeatureStdExtZa64rs,
+                                       FeatureStdExtZihpm,
+                                       FeatureStdExtZihintpause,
+                                       FeatureStdExtB,
+                                       FeatureStdExtZic64b,
+                                       FeatureStdExtZicbom,
+                                       FeatureStdExtZicbop,
+                                       FeatureStdExtZicboz,
+                                       FeatureStdExtZfhmin,
+                                       FeatureStdExtZkt,
+                                       FeatureStdExtV,
                                        FeatureStdExtZifencei,
                                        FeatureStdExtZihintntl,
                                        FeatureStdExtZvl128b,
@@ -368,7 +410,7 @@ def SIFIVE_P470 : RISCVProcessorModel<"sifive-p470", SiFiveP400Model,
                                        FeatureVendorXSiFivecdiscarddlone,
                                        FeatureVendorXSiFivecflushdlone,
                                        FeatureUnalignedScalarMem,
-                                       FeatureUnalignedVectorMem]),
+                                       FeatureUnalignedVectorMem],
                                       !listconcat(SiFiveP400TuneFeatures,
                                                   [TuneNoSinkSplatOperands,
                                                    TuneVXRMPipelineFlush])>;
@@ -397,8 +439,29 @@ def SIFIVE_P550 : RISCVProcessorModel<"sifive-p550", SiFiveP500Model,
 }
 
 def SIFIVE_P670 : RISCVProcessorModel<"sifive-p670", SiFiveP600Model,
-                                      !listconcat(RVA22U64Features,
-                                      [FeatureStdExtV,
+                                      [Feature64Bit,
+                                       FeatureStdExtI,
+                                       FeatureStdExtM,
+                                       FeatureStdExtA,
+                                       FeatureStdExtF,
+                                       FeatureStdExtD,
+                                       FeatureStdExtC,
+                                       FeatureStdExtZicsr,
+                                       FeatureStdExtZiccif,
+                                       FeatureStdExtZiccrse,
+                                       FeatureStdExtZiccamoa,
+                                       FeatureStdExtZicclsm,
+                                       FeatureStdExtZa64rs,
+                                       FeatureStdExtZihpm,
+                                       FeatureStdExtZihintpause,
+                                       FeatureStdExtB,
+                                       FeatureStdExtZic64b,
+                                       FeatureStdExtZicbom,
+                                       FeatureStdExtZicbop,
+                                       FeatureStdExtZicboz,
+                                       FeatureStdExtZfhmin,
+                                       FeatureStdExtZkt,
+                                       FeatureStdExtV,
                                        FeatureStdExtZifencei,
                                        FeatureStdExtZihintntl,
                                        FeatureStdExtZvl128b,
@@ -408,7 +471,7 @@ def SIFIVE_P670 : RISCVProcessorModel<"sifive-p670", SiFiveP600Model,
                                        FeatureStdExtZvksc,
                                        FeatureStdExtZvksg,
                                        FeatureUnalignedScalarMem,
-                                       FeatureUnalignedVectorMem]),
+                                       FeatureUnalignedVectorMem],
                                       [TuneNoDefaultUnroll,
                                        TuneConditionalCompressedMoveFusion,
                                        TuneLUIADDIFusion,



More information about the llvm-commits mailing list