diff --git a/llvm/lib/Target/RISCV/RISCV.td b/llvm/lib/Target/RISCV/RISCV.td --- a/llvm/lib/Target/RISCV/RISCV.td +++ b/llvm/lib/Target/RISCV/RISCV.td @@ -430,6 +430,11 @@ def FeatureSaveRestore : SubtargetFeature<"save-restore", "EnableSaveRestore", "true", "Enable save/restore.">; +def FeatureUnalignedScalarMem + : SubtargetFeature<"unaligned-scalar-mem", "EnableUnalignedScalarMem", + "true", "Has reasonably performant unaligned scalar " + "loads and stores">; + def TuneNoDefaultUnroll : SubtargetFeature<"no-default-unroll", "EnableDefaultUnroll", "false", "Disable default unroll preference.">; diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp --- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp +++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp @@ -11787,9 +11787,13 @@ bool RISCVTargetLowering::allowsMisalignedMemoryAccesses( EVT VT, unsigned AddrSpace, Align Alignment, MachineMemOperand::Flags Flags, bool *Fast) const { - if (!VT.isVector()) - return false; + if (!VT.isVector()) { + if (Fast) + *Fast = false; + return Subtarget.enableUnalignedScalarMem(); + } + // All vector implementations must support element alignment EVT ElemVT = VT.getVectorElementType(); if (Alignment >= ElemVT.getStoreSize()) { if (Fast) diff --git a/llvm/lib/Target/RISCV/RISCVSubtarget.h b/llvm/lib/Target/RISCV/RISCVSubtarget.h --- a/llvm/lib/Target/RISCV/RISCVSubtarget.h +++ b/llvm/lib/Target/RISCV/RISCVSubtarget.h @@ -92,6 +92,7 @@ bool EnableRVCHintInstrs = true; bool EnableDefaultUnroll = true; bool EnableSaveRestore = false; + bool EnableUnalignedScalarMem = false; unsigned XLen = 32; unsigned ZvlLen = 0; MVT XLenVT = MVT::i32; @@ -182,6 +183,7 @@ bool enableRVCHintInstrs() const { return EnableRVCHintInstrs; } bool enableDefaultUnroll() const { return EnableDefaultUnroll; } bool enableSaveRestore() const { return EnableSaveRestore; } + bool enableUnalignedScalarMem() const { return EnableUnalignedScalarMem; } MVT getXLenVT() const { return XLenVT; } unsigned getXLen() const { return XLen; } unsigned getFLen() const { diff --git a/llvm/test/CodeGen/RISCV/unaligned-load-store.ll b/llvm/test/CodeGen/RISCV/unaligned-load-store.ll --- a/llvm/test/CodeGen/RISCV/unaligned-load-store.ll +++ b/llvm/test/CodeGen/RISCV/unaligned-load-store.ll @@ -1,43 +1,60 @@ ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py ; RUN: llc -mtriple=riscv32 -verify-machineinstrs < %s \ -; RUN: | FileCheck -check-prefixes=BOTH,RV32I %s +; RUN: | FileCheck -check-prefixes=ALL,NOMISALIGN,RV32I %s ; RUN: llc -mtriple=riscv64 -verify-machineinstrs < %s \ -; RUN: | FileCheck -check-prefixes=BOTH,RV64I %s +; RUN: | FileCheck -check-prefixes=ALL,NOMISALIGN,RV64I %s +; RUN: llc -mtriple=riscv32 -mattr=+unaligned-scalar-mem -verify-machineinstrs < %s \ +; RUN: | FileCheck -check-prefixes=ALL,MISALIGN,MISALIGN-RV32I %s +; RUN: llc -mtriple=riscv64 -mattr=+unaligned-scalar-mem -verify-machineinstrs < %s \ +; RUN: | FileCheck -check-prefixes=ALL,MISALIGN,MISALIGN-RV64I %s ; A collection of cases showing codegen for unaligned loads and stores define i8 @load_i8(i8* %p) { -; BOTH-LABEL: load_i8: -; BOTH: # %bb.0: -; BOTH-NEXT: lb a0, 0(a0) -; BOTH-NEXT: ret +; ALL-LABEL: load_i8: +; ALL: # %bb.0: +; ALL-NEXT: lb a0, 0(a0) +; ALL-NEXT: ret %res = load i8, i8* %p, align 1 ret i8 %res } define i16 @load_i16(i16* %p) { -; BOTH-LABEL: load_i16: -; BOTH: # %bb.0: -; BOTH-NEXT: lb a1, 1(a0) -; BOTH-NEXT: lbu a0, 0(a0) -; BOTH-NEXT: slli a1, a1, 8 -; BOTH-NEXT: or a0, a1, a0 -; BOTH-NEXT: ret +; NOMISALIGN-LABEL: load_i16: +; NOMISALIGN: # %bb.0: +; NOMISALIGN-NEXT: lb a1, 1(a0) +; NOMISALIGN-NEXT: lbu a0, 0(a0) +; NOMISALIGN-NEXT: slli a1, a1, 8 +; NOMISALIGN-NEXT: or a0, a1, a0 +; NOMISALIGN-NEXT: ret +; +; MISALIGN-LABEL: load_i16: +; MISALIGN: # %bb.0: +; MISALIGN-NEXT: lh a0, 0(a0) +; MISALIGN-NEXT: ret %res = load i16, i16* %p, align 1 ret i16 %res } define i24 @load_i24(i24* %p) { -; BOTH-LABEL: load_i24: -; BOTH: # %bb.0: -; BOTH-NEXT: lbu a1, 1(a0) -; BOTH-NEXT: lbu a2, 0(a0) -; BOTH-NEXT: lb a0, 2(a0) -; BOTH-NEXT: slli a1, a1, 8 -; BOTH-NEXT: or a1, a1, a2 -; BOTH-NEXT: slli a0, a0, 16 -; BOTH-NEXT: or a0, a1, a0 -; BOTH-NEXT: ret +; NOMISALIGN-LABEL: load_i24: +; NOMISALIGN: # %bb.0: +; NOMISALIGN-NEXT: lbu a1, 1(a0) +; NOMISALIGN-NEXT: lbu a2, 0(a0) +; NOMISALIGN-NEXT: lb a0, 2(a0) +; NOMISALIGN-NEXT: slli a1, a1, 8 +; NOMISALIGN-NEXT: or a1, a1, a2 +; NOMISALIGN-NEXT: slli a0, a0, 16 +; NOMISALIGN-NEXT: or a0, a1, a0 +; NOMISALIGN-NEXT: ret +; +; MISALIGN-LABEL: load_i24: +; MISALIGN: # %bb.0: +; MISALIGN-NEXT: lb a1, 2(a0) +; MISALIGN-NEXT: lhu a0, 0(a0) +; MISALIGN-NEXT: slli a1, a1, 16 +; MISALIGN-NEXT: or a0, a0, a1 +; MISALIGN-NEXT: ret %res = load i24, i24* %p, align 1 ret i24 %res } @@ -70,6 +87,11 @@ ; RV64I-NEXT: slli a0, a0, 16 ; RV64I-NEXT: or a0, a0, a1 ; RV64I-NEXT: ret +; +; MISALIGN-LABEL: load_i32: +; MISALIGN: # %bb.0: +; MISALIGN-NEXT: lw a0, 0(a0) +; MISALIGN-NEXT: ret %res = load i32, i32* %p, align 1 ret i32 %res } @@ -125,54 +147,83 @@ ; RV64I-NEXT: slli a0, a0, 32 ; RV64I-NEXT: or a0, a0, a1 ; RV64I-NEXT: ret +; +; MISALIGN-RV32I-LABEL: load_i64: +; MISALIGN-RV32I: # %bb.0: +; MISALIGN-RV32I-NEXT: lw a2, 0(a0) +; MISALIGN-RV32I-NEXT: lw a1, 4(a0) +; MISALIGN-RV32I-NEXT: mv a0, a2 +; MISALIGN-RV32I-NEXT: ret +; +; MISALIGN-RV64I-LABEL: load_i64: +; MISALIGN-RV64I: # %bb.0: +; MISALIGN-RV64I-NEXT: ld a0, 0(a0) +; MISALIGN-RV64I-NEXT: ret %res = load i64, i64* %p, align 1 ret i64 %res } define void @store_i8(i8* %p, i8 %v) { -; BOTH-LABEL: store_i8: -; BOTH: # %bb.0: -; BOTH-NEXT: sb a1, 0(a0) -; BOTH-NEXT: ret +; ALL-LABEL: store_i8: +; ALL: # %bb.0: +; ALL-NEXT: sb a1, 0(a0) +; ALL-NEXT: ret store i8 %v, i8* %p, align 1 ret void } define void @store_i16(i16* %p, i16 %v) { -; BOTH-LABEL: store_i16: -; BOTH: # %bb.0: -; BOTH-NEXT: sb a1, 0(a0) -; BOTH-NEXT: srli a1, a1, 8 -; BOTH-NEXT: sb a1, 1(a0) -; BOTH-NEXT: ret +; NOMISALIGN-LABEL: store_i16: +; NOMISALIGN: # %bb.0: +; NOMISALIGN-NEXT: sb a1, 0(a0) +; NOMISALIGN-NEXT: srli a1, a1, 8 +; NOMISALIGN-NEXT: sb a1, 1(a0) +; NOMISALIGN-NEXT: ret +; +; MISALIGN-LABEL: store_i16: +; MISALIGN: # %bb.0: +; MISALIGN-NEXT: sh a1, 0(a0) +; MISALIGN-NEXT: ret store i16 %v, i16* %p, align 1 ret void } define void @store_i24(i24* %p, i24 %v) { -; BOTH-LABEL: store_i24: -; BOTH: # %bb.0: -; BOTH-NEXT: sb a1, 0(a0) -; BOTH-NEXT: srli a2, a1, 8 -; BOTH-NEXT: sb a2, 1(a0) -; BOTH-NEXT: srli a1, a1, 16 -; BOTH-NEXT: sb a1, 2(a0) -; BOTH-NEXT: ret +; NOMISALIGN-LABEL: store_i24: +; NOMISALIGN: # %bb.0: +; NOMISALIGN-NEXT: sb a1, 0(a0) +; NOMISALIGN-NEXT: srli a2, a1, 8 +; NOMISALIGN-NEXT: sb a2, 1(a0) +; NOMISALIGN-NEXT: srli a1, a1, 16 +; NOMISALIGN-NEXT: sb a1, 2(a0) +; NOMISALIGN-NEXT: ret +; +; MISALIGN-LABEL: store_i24: +; MISALIGN: # %bb.0: +; MISALIGN-NEXT: sh a1, 0(a0) +; MISALIGN-NEXT: srli a1, a1, 16 +; MISALIGN-NEXT: sb a1, 2(a0) +; MISALIGN-NEXT: ret store i24 %v, i24* %p, align 1 ret void } define void @store_i32(i32* %p, i32 %v) { -; BOTH-LABEL: store_i32: -; BOTH: # %bb.0: -; BOTH-NEXT: sb a1, 0(a0) -; BOTH-NEXT: srli a2, a1, 24 -; BOTH-NEXT: sb a2, 3(a0) -; BOTH-NEXT: srli a2, a1, 16 -; BOTH-NEXT: sb a2, 2(a0) -; BOTH-NEXT: srli a1, a1, 8 -; BOTH-NEXT: sb a1, 1(a0) -; BOTH-NEXT: ret +; NOMISALIGN-LABEL: store_i32: +; NOMISALIGN: # %bb.0: +; NOMISALIGN-NEXT: sb a1, 0(a0) +; NOMISALIGN-NEXT: srli a2, a1, 24 +; NOMISALIGN-NEXT: sb a2, 3(a0) +; NOMISALIGN-NEXT: srli a2, a1, 16 +; NOMISALIGN-NEXT: sb a2, 2(a0) +; NOMISALIGN-NEXT: srli a1, a1, 8 +; NOMISALIGN-NEXT: sb a1, 1(a0) +; NOMISALIGN-NEXT: ret +; +; MISALIGN-LABEL: store_i32: +; MISALIGN: # %bb.0: +; MISALIGN-NEXT: sw a1, 0(a0) +; MISALIGN-NEXT: ret store i32 %v, i32* %p, align 1 ret void } @@ -214,6 +265,17 @@ ; RV64I-NEXT: srli a1, a1, 8 ; RV64I-NEXT: sb a1, 1(a0) ; RV64I-NEXT: ret +; +; MISALIGN-RV32I-LABEL: store_i64: +; MISALIGN-RV32I: # %bb.0: +; MISALIGN-RV32I-NEXT: sw a2, 4(a0) +; MISALIGN-RV32I-NEXT: sw a1, 0(a0) +; MISALIGN-RV32I-NEXT: ret +; +; MISALIGN-RV64I-LABEL: store_i64: +; MISALIGN-RV64I: # %bb.0: +; MISALIGN-RV64I-NEXT: sd a1, 0(a0) +; MISALIGN-RV64I-NEXT: ret store i64 %v, i64* %p, align 1 ret void }