[RISCV] Add zihintntl instructions

[craig.topper]

llvm/lib/Target/RISCV/RISCV.td

53

zihintpause?

[achieveartificialintelligence]

Fix typo

[• s]

Add preprocessor test

[sunshaoce]

Rebase

[kito-cheng]

LGTM

[joshua-arch1]

It seems that llvm implementation is different from Binutils/GCC. Binutils didn't regard ntl instructions as aliases of add since encoding space is reserved for HINT instructions.

[asb]

In D121670#4192158, @joshua-arch1 wrote:

It seems that llvm implementation is different from Binutils/GCC. Binutils didn't regard ntl instructions as aliases of add since encoding space is reserved for HINT instructions.

How does this different implementation approach show up in terms of user-visible behaviour?

Looking at the ISA spec, I think the use of the term "reserved" with respect to hint instructions is unfortunate, because I don't think the intended meaning isn't that they are considered a "reserved" encoding as defined in the categories of instructions, as otherwise it would be legal for implementations to trap when encountering a hint, making them impossible to deploy in a backward compatible way.

[asb]

I've created a PR on the ISA manual to try to clarify the confusing overloaded use of the term "reserved" https://github.com/riscv/riscv-isa-manual/pull/990

llvm/lib/Support/RISCVISAInfo.cpp

static const RISCVSupportedExtension SupportedExtensions[] = {
     {"zve32x", RISCVExtensionVersion{1, 0}},
     {"zve32f", RISCVExtensionVersion{1, 0}},
     {"zve64x", RISCVExtensionVersion{1, 0}},
     {"zve64f", RISCVExtensionVersion{1, 0}},
     {"zve64d", RISCVExtensionVersion{1, 0}},
 };
 
 static const RISCVSupportedExtension SupportedExperimentalExtensions[] = {
+    {"zihintntl", RISCVExtensionVersion{0, 2}},
+
     {"zbe", RISCVExtensionVersion{0, 93}},
     {"zbf", RISCVExtensionVersion{0, 93}},
     {"zbm", RISCVExtensionVersion{0, 93}},
     {"zbp", RISCVExtensionVersion{0, 93}},
     {"zbr", RISCVExtensionVersion{0, 93}},
     {"zbt", RISCVExtensionVersion{0, 93}},
 };
 

llvm/lib/Target/RISCV/RISCV.td

 
 def FeatureStdExtZihintpause
     : SubtargetFeature<"zihintpause", "HasStdExtZihintpause", "true",
                        "'zihintpause' (Pause Hint)">;
 def HasStdExtZihintpause : Predicate<"Subtarget->hasStdExtZihintpause()">,
                                      AssemblerPredicate<(all_of FeatureStdExtZihintpause),
                                      "'Zihintpause' (Pause Hint)">;
 
+def FeatureStdExtZihintntl
+    : SubtargetFeature<"experimental-zihintntl", "HasStdExtZihintntl", "true",
+                       "'zihintntl' (Non-Temporal Locality Hints)">;
+def HasStdExtZihintntl : Predicate<"Subtarget->hasStdExtZihintntl()">,
+                                    AssemblerPredicate<(all_of FeatureStdExtZihintntl),
+                                    "'Zihintntl' (Non-Temporal Locality Hints)">;
+
 def FeatureStdExtZfhmin
     : SubtargetFeature<"zfhmin", "HasStdExtZfhmin", "true",
                        "'Zfhmin' (Half-Precision Floating-Point Minimal)",
                        [FeatureStdExtF]>;
 def HasStdExtZfhmin : Predicate<"Subtarget->hasStdExtZfhmin()">,
                              AssemblerPredicate<(all_of FeatureStdExtZfhmin),
                              "'Zfhmin' (Half-Precision Floating-Point Minimal)">;
 

llvm/lib/Target/RISCV/RISCVInstrInfo.td

 def : InstAlias<"sfence.vma $rs", (SFENCE_VMA GPR:$rs, X0)>;
 
 def : InstAlias<"hfence.gvma",     (HFENCE_GVMA      X0, X0)>;
 def : InstAlias<"hfence.gvma $rs", (HFENCE_GVMA GPR:$rs, X0)>;
 
 def : InstAlias<"hfence.vvma",     (HFENCE_VVMA      X0, X0)>;
 def : InstAlias<"hfence.vvma $rs", (HFENCE_VVMA GPR:$rs, X0)>;
 
+let Predicates = [HasStdExtZihintntl] in {
+  def : InstAlias<"ntl.p1",     (ADD   X0, X0, X2)>;
+  def : InstAlias<"ntl.pall",   (ADD   X0, X0, X3)>;
+  def : InstAlias<"ntl.s1",     (ADD   X0, X0, X4)>;
+  def : InstAlias<"ntl.all",    (ADD   X0, X0, X5)>;
+} // Predicates = [HasStdExtZihintntl]
+
 let EmitPriority = 0 in {
 def : InstAlias<"lb $rd, (${rs1})",
                 (LB  GPR:$rd, GPR:$rs1, 0)>;
 def : InstAlias<"lh $rd, (${rs1})",
                 (LH  GPR:$rd, GPR:$rs1, 0)>;
 def : InstAlias<"lw $rd, (${rs1})",
                 (LW  GPR:$rd, GPR:$rs1, 0)>;
 def : InstAlias<"lbu $rd, (${rs1})",

llvm/lib/Target/RISCV/RISCVSubtarget.h

private:
   RISCVProcFamilyEnum RISCVProcFamily = Others;
 
   bool HasStdExtM = false;
   bool HasStdExtA = false;
   bool HasStdExtF = false;
   bool HasStdExtD = false;
   bool HasStdExtC = false;
   bool HasStdExtZihintpause = false;
+  bool HasStdExtZihintntl = false;
   bool HasStdExtZba = false;
   bool HasStdExtZbb = false;
   bool HasStdExtZbc = false;
   bool HasStdExtZbe = false;
   bool HasStdExtZbf = false;
   bool HasStdExtZbm = false;
   bool HasStdExtZbp = false;
   bool HasStdExtZbr = false;
public:
 
   bool hasStdExtM() const { return HasStdExtM; }
   bool hasStdExtA() const { return HasStdExtA; }
   bool hasStdExtF() const { return HasStdExtF; }
   bool hasStdExtD() const { return HasStdExtD; }
   bool hasStdExtC() const { return HasStdExtC; }
   bool hasStdExtV() const { return HasStdExtV; }
   bool hasStdExtZihintpause() const { return HasStdExtZihintpause; }
+  bool hasStdExtZihintntl() const { return HasStdExtZihintntl; }
   bool hasStdExtZba() const { return HasStdExtZba; }
   bool hasStdExtZbb() const { return HasStdExtZbb; }
   bool hasStdExtZbc() const { return HasStdExtZbc; }
   bool hasStdExtZbe() const { return HasStdExtZbe; }
   bool hasStdExtZbf() const { return HasStdExtZbf; }
   bool hasStdExtZbm() const { return HasStdExtZbm; }
   bool hasStdExtZbp() const { return HasStdExtZbp; }
   bool hasStdExtZbr() const { return HasStdExtZbr; }

llvm/test/CodeGen/RISCV/attributes.ll

 ;; Generate ELF attributes from llc.
 
 ; RUN: llc -mtriple=riscv32 -mattr=+m %s -o - | FileCheck --check-prefix=RV32M %s
 ; RUN: llc -mtriple=riscv32 -mattr=+a %s -o - | FileCheck --check-prefix=RV32A %s
 ; RUN: llc -mtriple=riscv32 -mattr=+f %s -o - | FileCheck --check-prefix=RV32F %s
 ; RUN: llc -mtriple=riscv32 -mattr=+d %s -o - | FileCheck --check-prefix=RV32D %s
 ; RUN: llc -mtriple=riscv32 -mattr=+c %s -o - | FileCheck --check-prefix=RV32C %s
 ; RUN: llc -mtriple=riscv32 -mattr=+zihintpause %s -o - | FileCheck --check-prefix=RV32ZIHINTPAUSE %s
+; RUN: llc -mtriple=riscv32 -mattr=+experimental-zihintntl %s -o - | FileCheck --check-prefix=RV32ZIHINTNTL %s
 ; RUN: llc -mtriple=riscv32 -mattr=+zfhmin %s -o - | FileCheck --check-prefix=RV32ZFHMIN %s
 ; RUN: llc -mtriple=riscv32 -mattr=+zfh %s -o - | FileCheck --check-prefix=RV32ZFH %s
 ; RUN: llc -mtriple=riscv32 -mattr=+zba %s -o - | FileCheck --check-prefix=RV32ZBA %s
 ; RUN: llc -mtriple=riscv32 -mattr=+zbb %s -o - | FileCheck --check-prefix=RV32ZBB %s
 ; RUN: llc -mtriple=riscv32 -mattr=+zbc %s -o - | FileCheck --check-prefix=RV32ZBC %s
 ; RUN: llc -mtriple=riscv32 -mattr=+experimental-zbe %s -o - | FileCheck --check-prefix=RV32ZBE %s
 ; RUN: llc -mtriple=riscv32 -mattr=+experimental-zbf %s -o - | FileCheck --check-prefix=RV32ZBF %s
 ; RUN: llc -mtriple=riscv32 -mattr=+experimental-zbm %s -o - | FileCheck --check-prefix=RV32ZBM %s

 ; RUN: llc -mtriple=riscv32 -mattr=+zbkb,+zbkc,+zbkx,+zkne,+zknd,+zknh %s -o - | FileCheck --check-prefix=RV32COMBINEINTOZKN %s
 ; RUN: llc -mtriple=riscv32 -mattr=+zbkb,+zbkc,+zbkx,+zksed,+zksh %s -o - | FileCheck --check-prefix=RV32COMBINEINTOZKS %s
 ; RUN: llc -mtriple=riscv64 -mattr=+m %s -o - | FileCheck --check-prefix=RV64M %s
 ; RUN: llc -mtriple=riscv64 -mattr=+a %s -o - | FileCheck --check-prefix=RV64A %s
 ; RUN: llc -mtriple=riscv64 -mattr=+f %s -o - | FileCheck --check-prefix=RV64F %s
 ; RUN: llc -mtriple=riscv64 -mattr=+d %s -o - | FileCheck --check-prefix=RV64D %s
 ; RUN: llc -mtriple=riscv64 -mattr=+c %s -o - | FileCheck --check-prefix=RV64C %s
 ; RUN: llc -mtriple=riscv64 -mattr=+zihintpause %s -o - | FileCheck --check-prefix=RV64ZIHINTPAUSE %s
+; RUN: llc -mtriple=riscv64 -mattr=+experimental-zihintntl %s -o - | FileCheck --check-prefix=RV64ZIHINTNTL %s
 ; RUN: llc -mtriple=riscv64 -mattr=+zfhmin %s -o - | FileCheck --check-prefix=RV64ZFHMIN %s
 ; RUN: llc -mtriple=riscv64 -mattr=+zfh %s -o - | FileCheck --check-prefix=RV64ZFH %s
 ; RUN: llc -mtriple=riscv64 -mattr=+zba %s -o - | FileCheck --check-prefix=RV64ZBA %s
 ; RUN: llc -mtriple=riscv64 -mattr=+zbb %s -o - | FileCheck --check-prefix=RV64ZBB %s
 ; RUN: llc -mtriple=riscv64 -mattr=+zbc %s -o - | FileCheck --check-prefix=RV64ZBC %s
 ; RUN: llc -mtriple=riscv64 -mattr=+experimental-zbe %s -o - | FileCheck --check-prefix=RV64ZBE %s
 ; RUN: llc -mtriple=riscv64 -mattr=+experimental-zbf %s -o - | FileCheck --check-prefix=RV64ZBF %s
 ; RUN: llc -mtriple=riscv64 -mattr=+experimental-zbm %s -o - | FileCheck --check-prefix=RV64ZBM %s

 ; RUN: llc -mtriple=riscv64 -mattr=+zbkb,+zbkc,+zbkx,+zksed,+zksh %s -o - | FileCheck --check-prefix=RV64COMBINEINTOZKS %s
 
 ; RV32M: .attribute 5, "rv32i2p0_m2p0"
 ; RV32A: .attribute 5, "rv32i2p0_a2p0"
 ; RV32F: .attribute 5, "rv32i2p0_f2p0"
 ; RV32D: .attribute 5, "rv32i2p0_f2p0_d2p0"
 ; RV32C: .attribute 5, "rv32i2p0_c2p0"
 ; RV32ZIHINTPAUSE: .attribute 5, "rv32i2p0_zihintpause2p0"
+; RV32ZIHINTNTL: .attribute 5, "rv32i2p0_zihintntl0p2"
 ; RV32ZFHMIN: .attribute 5, "rv32i2p0_f2p0_zfhmin1p0"
 ; RV32ZFH: .attribute 5, "rv32i2p0_f2p0_zfh1p0"
 ; RV32ZBA: .attribute 5, "rv32i2p0_zba1p0"
 ; RV32ZBB: .attribute 5, "rv32i2p0_zbb1p0"
 ; RV32ZBC: .attribute 5, "rv32i2p0_zbc1p0"
 ; RV32ZBE: .attribute 5, "rv32i2p0_zbe0p93"
 ; RV32ZBF: .attribute 5, "rv32i2p0_zbf0p93"
 ; RV32ZBM: .attribute 5, "rv32i2p0_zbm0p93"

 ; RV32COMBINEINTOZKS: .attribute 5, "rv32i2p0_zbkb1p0_zbkc1p0_zbkx1p0_zks1p0_zksed1p0_zksh1p0"
 
 ; RV64M: .attribute 5, "rv64i2p0_m2p0"
 ; RV64A: .attribute 5, "rv64i2p0_a2p0"
 ; RV64F: .attribute 5, "rv64i2p0_f2p0"
 ; RV64D: .attribute 5, "rv64i2p0_f2p0_d2p0"
 ; RV64C: .attribute 5, "rv64i2p0_c2p0"
 ; RV64ZIHINTPAUSE: .attribute 5, "rv64i2p0_zihintpause2p0"
+; RV64ZIHINTNTL: .attribute 5, "rv64i2p0_zihintntl0p2"
 ; RV64ZFHMIN: .attribute 5, "rv64i2p0_f2p0_zfhmin1p0"
 ; RV64ZFH: .attribute 5, "rv64i2p0_f2p0_zfh1p0"
 ; RV64ZBA: .attribute 5, "rv64i2p0_zba1p0"
 ; RV64ZBB: .attribute 5, "rv64i2p0_zbb1p0"
 ; RV64ZBC: .attribute 5, "rv64i2p0_zbc1p0"
 ; RV64ZBE: .attribute 5, "rv64i2p0_zbe0p93"
 ; RV64ZBF: .attribute 5, "rv64i2p0_zbf0p93"
 ; RV64ZBM: .attribute 5, "rv64i2p0_zbm0p93"

llvm/test/MC/RISCV/rv32zihintntl-valid.s

+# RUN: llvm-mc %s -triple=riscv32 -mattr=+experimental-zihintntl -riscv-no-aliases -show-encoding \
+# RUN:     | FileCheck -check-prefixes=CHECK-ASM,CHECK-ASM-AND-OBJ %s
+# RUN: llvm-mc %s -triple=riscv64 -mattr=+experimental-zihintntl -riscv-no-aliases -show-encoding \
+# RUN:     | FileCheck -check-prefixes=CHECK-ASM,CHECK-ASM-AND-OBJ %s
+# RUN: llvm-mc -filetype=obj -triple=riscv32 -mattr=+experimental-zihintntl < %s \
+# RUN:     | llvm-objdump --mattr=+experimental-zihintntl -M no-aliases -d -r - \
+# RUN:     | FileCheck --check-prefix=CHECK-ASM-AND-OBJ %s
+# RUN: llvm-mc -filetype=obj -triple=riscv64 -mattr=+experimental-zihintntl < %s \
+# RUN:     | llvm-objdump --mattr=+experimental-zihintntl -M no-aliases -d -r - \
+# RUN:     | FileCheck --check-prefix=CHECK-ASM-AND-OBJ %s
+
+# CHECK-ASM-AND-OBJ: add zero, zero, sp
+# CHECK-ASM: encoding: [0x33,0x00,0x20,0x00]
+ntl.p1
+
+# CHECK-ASM-AND-OBJ: add zero, zero, gp
+# CHECK-ASM: encoding: [0x33,0x00,0x30,0x00]
+ntl.pall
+
+# CHECK-ASM-AND-OBJ: add zero, zero, tp
+# CHECK-ASM: encoding: [0x33,0x00,0x40,0x00]
+ntl.s1
+
+# CHECK-ASM-AND-OBJ: add zero, zero, t0
+# CHECK-ASM: encoding: [0x33,0x00,0x50,0x00]
+ntl.all