[RISCV][CFI] add function epilogue cfi information (#110810)

This patch adds CFI instructions in the function epilogue.

Before patch:
addi sp, s0, -32
ld ra, 24(sp) # 8-byte Folded Reload
ld s

[RISCV][CFI] add function epilogue cfi information (#110810)

This patch adds CFI instructions in the function epilogue.

Before patch:
addi sp, s0, -32
ld ra, 24(sp) # 8-byte Folded Reload
ld s0, 16(sp) # 8-byte Folded Reload
ld s1, 8(sp) # 8-byte Folded Reload
addi sp, sp, 32
ret

After patch:
addi sp, s0, -32
.cfi_def_cfa sp, 32
ld ra, 24(sp) # 8-byte Folded Reload
ld s0, 16(sp) # 8-byte Folded Reload
ld s1, 8(sp) # 8-byte Folded Reload
.cfi_restore ra
.cfi_restore s0
.cfi_restore s1
addi sp, sp, 32
.cfi_def_cfa_offset 0
ret

This functionality is already present in `riscv-gcc`, but it’s not in
`clang` and this slightly impairs the `lldb` debugging experience, e.g.
backtrace.

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[RISCV] Inline Assembly: RVC constraint and N modifier (#112561)

This change implements support for the `cr` and `cf` register
constraints (which allocate a RVC GPR or RVC FPR respectively), and th

[RISCV] Inline Assembly: RVC constraint and N modifier (#112561)

This change implements support for the `cr` and `cf` register
constraints (which allocate a RVC GPR or RVC FPR respectively), and the
`N` modifier (which prints the raw encoding of a register rather than
the name).

The intention behind these additions is to make it easier to use inline
assembly when assembling raw instructions that are not supported by the
compiler, for instance when experimenting with new instructions or when
supporting proprietary extensions outside the toolchain.

These implement part of my proposal in riscv-non-isa/riscv-c-api-doc#92

As part of the implementation, I felt there was not enough coverage of
inline assembly and the "in X" floating-point extensions, so I have
added more regression tests around these configurations.

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[RISCV] Move compressible registers to the beginning of the FP allocation order.

We don't have very many compressible FP instructions, just load and store.
These instruction require the FP register

[RISCV] Move compressible registers to the beginning of the FP allocation order.

We don't have very many compressible FP instructions, just load and store.
These instruction require the FP register to be f8-f15.

This patch changes the FP allocation order to prioritize f10-f15 first.
These are also the FP argument registers. So I allocated them in reverse
order starting at f15 to avoid taking the first argument registers.
This appears to match gcc allocation order.

Reviewed By: asb

Differential Revision: https://reviews.llvm.org/D146488

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[RISCV] Convert some tests to opaque pointers (NFC)

[RISCV] More correctly ignore Zfinx register classes in getRegForInlineAsmConstraint.

Until Zfinx is supported in CodeGen we need to convert all Zfinx
register classes to GPR.

Remove the zfinx-type

[RISCV] More correctly ignore Zfinx register classes in getRegForInlineAsmConstraint.

Until Zfinx is supported in CodeGen we need to convert all Zfinx
register classes to GPR.

Remove the zfinx-types.ll test which didn't test anything meaningful
since -mattr=zfinx isn't implemented completely in llc.

Follow up to D93298.

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[RISCV] Update computeTargetABI from llc as well as clang

Clang computes the default ABI if -mabi is empty
and encode it in LLVM IR module flag since D105555.
For correctness, llc need to give the s

[RISCV] Update computeTargetABI from llc as well as clang

Clang computes the default ABI if -mabi is empty
and encode it in LLVM IR module flag since D105555.
For correctness, llc need to give the same target-abi
(Options.MCOptions.ABIName) with ABI encoded in IR.
The getSubtargetImpl already has a check for them only if
Options.MCOptions.ABIName is not empty.

In order to get more robustness we could have a check for
explicit ABI, but now we have two different logic to
compute the default ABI.

The front-end ABI is defautl to the ilp32/ilp32e/lp64, and
ilp32d/lp64d when hardware support for extension D.
The backend ABI is default to the ilp32/ilp32e/lp64.

Reviewed by: asb, jrtc27

Differential Revision: https://reviews.llvm.org/D118333

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[RISCV] Honor the VT when converting float point register names to register class for inline assembly.

It appears the code here was written for the inline asm clobbering
a specific register, but it

[RISCV] Honor the VT when converting float point register names to register class for inline assembly.

It appears the code here was written for the inline asm clobbering
a specific register, but it also gets used for named input and
output registers.

For the input and output case, we should honor the VT so we
don't insert conversion instructions around the inline assembly.

For the clobber, case we need to pick the largest register class.

Reviewed By: asb, jrtc27

Differential Revision: https://reviews.llvm.org/D117279

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[RISCV] Remove unused check prefixes. NFC

[RISCV] Add inline asm f32 test cases with D extension. NFC

Using named registers as input or output constraints creates fcvt.d.s
and fcvt.s.d instructions around the inline assembly.

This makes th

[RISCV] Add inline asm f32 test cases with D extension. NFC

Using named registers as input or output constraints creates fcvt.d.s
and fcvt.s.d instructions around the inline assembly.

This makes the data unusable by the inline assembly and corrupts
the results of the inline assembly.

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[RISCV] Switch to the Machine Scheduler

Most of the test changes are trivial instruction reorderings and differing
register allocations, without any obvious performance impact.

Differential Revisio

[RISCV] Switch to the Machine Scheduler

Most of the test changes are trivial instruction reorderings and differing
register allocations, without any obvious performance impact.

Differential Revision: https://reviews.llvm.org/D66973

llvm-svn: 372106

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Revert Patch from Phabricator

This reverts r372092 (git commit e38695a0255c9e7b53639f349f8101bae1ce5c04)

llvm-svn: 372104

Patch from Phabricator

llvm-svn: 372092

[RISCV] Allow ABI Names in Inline Assembly Constraints

Summary:
Clang will replace references to registers using ABI names in inline
assembly constraints with references to architecture names, but o

[RISCV] Allow ABI Names in Inline Assembly Constraints

Summary:
Clang will replace references to registers using ABI names in inline
assembly constraints with references to architecture names, but other
frontends do not. LLVM uses the regular assembly parser to parse inline asm,
so inline assembly strings can contain references to registers using their
ABI names.

This patch adds support for parsing constraints using either the ABI name or
the architectural register name. This means we do not need to implement the
ABI name replacement code in every single frontend, especially those like
Rust which are a very thin shim on top of LLVM IR's inline asm, and that
constraints can more closely match the assembly strings they refer to.

Reviewers: asb, simoncook

Reviewed By: simoncook

Subscribers: hiraditya, rbar, johnrusso, JDevlieghere, apazos, sabuasal, niosHD, kito-cheng, shiva0217, jrtc27, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, s.egerton, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65947

llvm-svn: 368303

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[RISCV] Support 'f' Inline Assembly Constraint

Summary:
This adds the 'f' inline assembly constraint, as supported by GCC. An
'f'-constrained operand is passed in a floating point register. Exactly

[RISCV] Support 'f' Inline Assembly Constraint

Summary:
This adds the 'f' inline assembly constraint, as supported by GCC. An
'f'-constrained operand is passed in a floating point register. Exactly
which kind of floating-point register (32-bit or 64-bit) is decided
based on the operand type and the available standard extensions (-f and
-d, respectively).

This patch adds support in both the clang frontend, and LLVM itself.

Reviewers: asb, lewis-revill

Reviewed By: asb

Subscribers: hiraditya, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, kito-cheng, shiva0217, jrtc27, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, s.egerton, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D65500

llvm-svn: 367403

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