(but I see you're using
... If you want to tie into the greater embedded-rust ecosystem, switching to
ruduino... If you want to tie into the greater embedded-rust ecosystem, switching to
avr-hal instead might be worthwhile)
thanks very much for pointing me to them (and writing them!)
Assertion failed: (Imm <= 62 && "Offset is out of range"), function expand, file ../lib/Target/AVR/AVRExpandPseudoInsts.cpp, line 1164
This kind of thing?
Hi it's been a long time but I'm slowly plugging away at things and thought you all might like to see my sdcard library that I'm working on: https://github.com/drmorr0/sdfat32-rs
It only can
ls in the root directory of a card and has no batteries included (requires a custom LLVM build, among other things) but it's getting there!
@ayke yeah… I think there’s a bit of a convoluted mix of hacks on hacks that led to this place and they break sometimes. I think the only long term solution is probably re-engineering it. It sounds a bit weird using AVR specific pseudo instructions to write frame lowering? Isn’t it easier to just write the stack frame emission all in C++ code? Anyway I’m just speculating. I’d like to look if I ever get time. For now I’m trying to understand why it happens sometimes and not others, so I can tell users to work around those cases!
I actually happened to run into that issue yesterday. I believe there is code to deal with this case but apparently not all edge cases are handled.
Hi all!
I'm stuck and don't know where is problem.
When I'm converting f32 to usize in loop I'm always getting 0. Probably I miss some limitations for no_std or something similar.
I run this on Arduino Nano
#![no_std]
#![no_main]
use arduino_hal::prelude::*;
use panic_halt as _;
#[arduino_hal::entry]
fn main() -> ! {
let dp = arduino_hal::Peripherals::take().unwrap();
let pins = arduino_hal::pins!(dp);
let mut serial = arduino_hal::default_serial!(dp, pins, 57600);
let mut x: f32 = 3.0;
loop {
x = x + 1.0;
let b = x as usize;
ufmt::uwriteln!(&mut serial, "Got {}!\r", b).void_unwrap();
arduino_hal::delay_ms(1000);
}
}In serial I see only "Got 0!..."
If I move it from loop, then I'm getting correct value:
#![no_std]
#![no_main]
use arduino_hal::prelude::*;
use panic_halt as _;
#[arduino_hal::entry]
fn main() -> ! {
let dp = arduino_hal::Peripherals::take().unwrap();
let pins = arduino_hal::pins!(dp);
let mut serial = arduino_hal::default_serial!(dp, pins, 57600);
let mut x: f32 = 3.0;
x = x + 1.0;
let b = x as usize;
ufmt::uwriteln!(&mut serial, "Got {}!\r", b).void_unwrap();
arduino_hal::delay_ms(1000);
loop {
}
}Got 4!
Hello everyone I am looking to make some custom firmware for my usb rubber ducky from the original firmware source https://github.com/hak5darren/USB-Rubber-Ducky/blob/master/Firmware/Source/Ducky_HID/Framework.config I have gathered that the chip is a Atmel AT32UC3B http://ww1.microchip.com/downloads/en/DeviceDoc/doc32059.pdf and its avr32. I've tried to build the example avr target project thing (build --target avr-unknown-gnu-atmega328 -Z build-std=core --all --release) but it always fails with the following error
Compiling compiler_builtins v0.1.49
Compiling avr-std-stub v1.0.3
LLVM ERROR: Not supported instr: <MCInst 312 <MCOperand Reg:1> <MCOperand Imm:13> <MCOperand Reg:41>>
error: could not compile
Process finished with exit code 101
Compiling avr-std-stub v1.0.3
LLVM ERROR: Not supported instr: <MCInst 312 <MCOperand Reg:1> <MCOperand Imm:13> <MCOperand Reg:41>>
error: could not compile
compiler_builtinsProcess finished with exit code 101
Can someone help me get this setup properly or fix this error
(use the
FixedI16 and FixedU16 types)
error: couldn't allocate input reg for constraint 'w'
--> /home/user/.cargo/registry/src/github.com-1ecc6299db9ec823/avr_delay-0.3.1/src/lib.rs:34:17
|
34 | unsafe {llvm_asm!("1: sbiw $0,1
| ^
warning: `avr_delay` (lib) generated 1 warning (1 duplicate)
error: build failed
Do I need to install an older rust compiler?
I'm compiling C code using clang and it's doing something weird.
Here's a simple test case. If I compile this C code...
#include <math.h>
float _log(float f) {
return log(f);
}
It creates this LLVM IR...
; Function Attrs: nounwind readnone
define dso_local float @_log(float %f) local_unnamed_addr #0 {
entry:
%0 = tail call float @llvm.log.f32(float %f)
ret float %0
}Disassembly of section .text._log:
00000000 <_log>:
0: 0e 94 00 00 call 0 ; 0x0 <_log>
0: R_AVR_CALL logf
4: 08 95 ret
I added the relocation for clarity. It looks like this whole process is special case. I assume there's something in clang that sees a call to the extern log() function and replaces it with an llvm intrinsic. Presumably that makes for efficient back end implementations on some llvm platforms. Very clever.
However it looks like perhaps our back end is broken here. Because on AVR there is no logf function/symbol in
libm.a. Only log is defined in avr-libc, (avr-libm) presumably because double and float are identical on this platform.
Has anyone seen this and can suggest a fix? Or where in the back end I should go looking for the code to fix?
It compiles without warnings for me with clang 12. And produces what looks like a valid file. I did not see any calls to logf tough.
1 reply
In
lib/Target/AVR/AVRISelLowering.cpp...
AVRTargetLowering::AVRTargetLowering(const AVRTargetMachine &TM,
const AVRSubtarget &STI)
: TargetLowering(TM), Subtarget(STI) {
...
// Trigonometric rtlib functions
setLibcallName(RTLIB::SIN_F32, "sin");
setLibcallName(RTLIB::COS_F32, "cos");
So it looks like that's fixed for those two.
Otherwise this function gets called...
static void ReplaceFPIntrinsicWithCall(CallInst *CI, const char *Fname,
const char *Dname,
const char *LDname) {
switch (CI->getArgOperand(0)->getType()->getTypeID()) {
default: llvm_unreachable("Invalid type in intrinsic");
case Type::FloatTyID:
ReplaceCallWith(Fname, CI, CI->arg_begin(), CI->arg_end(),
Type::getFloatTy(CI->getContext()));
break;
case Type::DoubleTyID:
ReplaceCallWith(Dname, CI, CI->arg_begin(), CI->arg_end(),
Type::getDoubleTy(CI->getContext()));
break;
case Type::X86_FP80TyID:
case Type::FP128TyID:
case Type::PPC_FP128TyID:
ReplaceCallWith(LDname, CI, CI->arg_begin(), CI->arg_end(),
CI->getArgOperand(0)->getType());
break;
}
}
Which outputs logf for 32 bit floats.
diff --git a/llvm/lib/Target/AVR/AVRISelLowering.cpp b/llvm/lib/Target/AVR/AVRISelLowering.cpp
index eb719415395b..1eff049ba2ea 100644
--- a/llvm/lib/Target/AVR/AVRISelLowering.cpp
+++ b/llvm/lib/Target/AVR/AVRISelLowering.cpp
@@ -227,6 +227,29 @@ AVRTargetLowering::AVRTargetLowering(const AVRTargetMachine &TM,
setLibcallName(RTLIB::SIN_F32, "sin");
setLibcallName(RTLIB::COS_F32, "cos");
+ // other functions in llvm rtlib or libc/libm
+ // these are hard coded different from normal
+ // libm because avr-libc doesn't have the float
+ // variants; float and double are identical on avr
+ setLibcallName(RTLIB::REM_F32, "fmod");
+ setLibcallName(RTLIB::LOG_F32, "log");
+ setLibcallName(RTLIB::CBRT_F32, "cbrt");
+
+ setLibcallName(RTLIB::FLOOR_F32, "floor");
+ setLibcallName(RTLIB::CEIL_F32, "ceil");
+ setLibcallName(RTLIB::EXP_F32, "exp");
+
+ setLibcallName(RTLIB::FMIN_F32, "fmin");
+ setLibcallName(RTLIB::FMAX_F32, "fmax");
+ setLibcallName(RTLIB::FMA_F32, "fma");
+
+ setLibcallName(RTLIB::LOG10_F32, "log10");
+ setLibcallName(RTLIB::POW_F32, "pow");
+ setLibcallName(RTLIB::TRUNC_F32, "trunc");
+ setLibcallName(RTLIB::ROUND_F32, "round");
+ setLibcallName(RTLIB::LROUND_F32, "lround");
+ setLibcallName(RTLIB::LRINT_F32, "lrint");
+
setMinFunctionAlignment(Align(2));
setMinimumJumpTableEntries(UINT_MAX);
}
Not sure how to submit patches these days. I'm used to github and PRs. :)