[GHC] #16354: LLVM Backend generates invalid assembly.
#16354: LLVM Backend generates invalid assembly. -------------------------------------+------------------------------------- Reporter: AndreasK | Owner: (none) Type: bug | Status: new Priority: high | Milestone: Component: Compiler | Version: 8.9 (LLVM) | Keywords: CodeGen | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- {{{ #!haskell module Main where import System.Random import qualified Data.Vector as V g1 = mkStdGen 0 :: StdGen v2 = take 10000 $ randoms g1 :: [Int] main :: IO () main = do undefined }}} {{{ $ /e/ghc_regSpill/inplace/bin/ghc-stage2.exe Repro.hs -O2 -fllvm -O2 Loaded package environment from C:\ghc\msys64\home\Andi\tmp\minmax\unpred\.ghc.environment.x86_64-mingw32-8.7.20190215 [1 of 1] Compiling Main ( Repro.hs, Repro.o ) C:\\ghc\\msys64\\tmp\\ghc385768_0\\ghc_6.s: Assembler messages: C:\\ghc\\msys64\\tmp\\ghc385768_0\\ghc_6.s:354: Error: junk at end of line, first unrecognized character is `,' `gcc.exe' failed in phase `Assembler'. (Exit code: 1) }}} I've reproduced this with ghc 8.4/8.6 and HEAD using llvm 7.0.1 on windows. It only occurs with -O2. The issues arise from these directives: {{{ .section .rdata,"dr",discard,__xmm@000000000000004e0000000000000000 }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16354 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16354: LLVM Backend generates invalid assembly. -------------------------------------+------------------------------------- Reporter: AndreasK | Owner: (none) Type: bug | Status: new Priority: high | Milestone: Component: Compiler (LLVM) | Version: 8.9 Resolution: | Keywords: CodeGen Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by AndreasK): As far as I can tell the issue is that the format used is only supported for ELF. See https://sourceware.org/binutils/docs/as/Section.html Assuming that is the reason hopefully we just need to pass an appropriate flag to llvm. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16354#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16354: LLVM Backend generates invalid assembly. -------------------------------------+------------------------------------- Reporter: AndreasK | Owner: (none) Type: bug | Status: new Priority: high | Milestone: Component: Compiler (LLVM) | Version: 8.9 Resolution: | Keywords: CodeGen Operating System: Windows | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by AndreasK): * os: Unknown/Multiple => Windows -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16354#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16354: LLVM Backend generates invalid assembly. -------------------------------------+------------------------------------- Reporter: AndreasK | Owner: (none) Type: bug | Status: new Priority: high | Milestone: Component: Compiler (LLVM) | Version: 8.9 Resolution: | Keywords: CodeGen Operating System: Windows | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by AndreasK): * Attachment "Repro.ll" added. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16354 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16354: LLVM Backend generates invalid assembly. -------------------------------------+------------------------------------- Reporter: AndreasK | Owner: (none) Type: bug | Status: new Priority: high | Milestone: Component: Compiler (LLVM) | Version: 8.9 Resolution: | Keywords: CodeGen Operating System: Windows | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by AndreasK): Steps to reproduce. {{{ Andi@Horzube MINGW64 ~/tmp/minmax/llvm $ opt -O3 Repro.ll > opt.bc Andi@Horzube MINGW64 ~/tmp/minmax/llvm $ llc opt.bc -o llc.s -O3 Andi@Horzube MINGW64 ~/tmp/minmax/llvm $ as llc.s llc.s: Assembler messages: llc.s:367: Error: junk at end of line, first unrecognized character is `,' }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16354#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16354: LLVM Backend generates invalid assembly. -------------------------------------+------------------------------------- Reporter: AndreasK | Owner: (none) Type: bug | Status: new Priority: high | Milestone: Component: Compiler (LLVM) | Version: 8.9 Resolution: | Keywords: CodeGen Operating System: Windows | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by AndreasK): The issue here is that the target "x86_64-unknown-windows" generates .section directives which are not supported for pe output by the assembler. As far as I can tell however "x86_64-unknown-windows" (or one of the synonyms) IS the proper target. So this seems to be an issue with llvm. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16354#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16354: LLVM Backend generates invalid assembly. -------------------------------------+------------------------------------- Reporter: AndreasK | Owner: (none) Type: bug | Status: new Priority: high | Milestone: Component: Compiler (LLVM) | Version: 8.9 Resolution: | Keywords: CodeGen Operating System: Windows | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by AndreasK): {{{ $ llc --version LLVM (http://llvm.org/): LLVM version 7.0.1 Optimized build. Default target: x86_64-w64-mingw32 Host CPU: skylake Registered Targets: aarch64 - AArch64 (little endian) aarch64_be - AArch64 (big endian) amdgcn - AMD GCN GPUs arm - ARM arm64 - ARM64 (little endian) armeb - ARM (big endian) bpf - BPF (host endian) bpfeb - BPF (big endian) bpfel - BPF (little endian) hexagon - Hexagon lanai - Lanai mips - Mips mips64 - Mips64 [experimental] mips64el - Mips64el [experimental] mipsel - Mipsel msp430 - MSP430 [experimental] nvptx - NVIDIA PTX 32-bit nvptx64 - NVIDIA PTX 64-bit ppc32 - PowerPC 32 ppc64 - PowerPC 64 ppc64le - PowerPC 64 LE r600 - AMD GPUs HD2XXX-HD6XXX sparc - Sparc sparcel - Sparc LE sparcv9 - Sparc V9 systemz - SystemZ thumb - Thumb thumbeb - Thumb (big endian) x86 - 32-bit X86: Pentium-Pro and above x86-64 - 64-bit X86: EM64T and AMD64 xcore - XCore }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16354#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16354: LLVM Backend generates invalid assembly. -------------------------------------+------------------------------------- Reporter: AndreasK | Owner: (none) Type: bug | Status: upstream Priority: high | Milestone: Component: Compiler (LLVM) | Version: 8.9 Resolution: | Keywords: CodeGen Operating System: Windows | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * status: new => upstream Comment: Report upstream as [[https://bugs.llvm.org/show_bug.cgi?id=40824 #40824]]. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16354#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16354: LLVM Backend generates invalid assembly. -------------------------------------+------------------------------------- Reporter: AndreasK | Owner: (none) Type: bug | Status: upstream Priority: high | Milestone: Component: Compiler (LLVM) | Version: 8.9 Resolution: | Keywords: CodeGen Operating System: Windows | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by AndreasK): {{{ $ as --version GNU assembler (GNU Binutils) 2.30 Copyright (C) 2018 Free Software Foundation, Inc. This program is free software; you may redistribute it under the terms of the GNU General Public License version 3 or later. This program has absolutely no warranty. This assembler was configured for a target of `x86_64-w64-mingw32'. }}} Windows 10 Pro - Build 17763 (64 Bit) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16354#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16354: LLVM Backend generates invalid assembly. -------------------------------------+------------------------------------- Reporter: AndreasK | Owner: (none) Type: bug | Status: upstream Priority: high | Milestone: Component: Compiler (LLVM) | Version: 8.9 Resolution: | Keywords: CodeGen Operating System: Windows | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by AndreasK): Going by the answers upstream our options are: * Switch to the llvm assembler llvm-mc for the llvm backend. * Hope binutils implements the llvm extensions eventually. * Go back to LLVM 6 -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16354#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16354: LLVM Backend generates invalid assembly. -------------------------------------+------------------------------------- Reporter: AndreasK | Owner: (none) Type: bug | Status: upstream Priority: high | Milestone: Component: Compiler (LLVM) | Version: 8.9 Resolution: | Keywords: CodeGen Operating System: Windows | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): I don't think it would be wise to let this issue hold us back on an old llvm release. However, the other options aren't much better. Ideally we would just use llvm-mc but this is easier said than done since we use invoke the assembler through gcc. Using as directly is complicated by the fact that we would then be responsible for running cpp ourselves. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16354#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16354: LLVM Backend generates invalid assembly. -------------------------------------+------------------------------------- Reporter: AndreasK | Owner: (none) Type: bug | Status: upstream Priority: high | Milestone: Component: Compiler (LLVM) | Version: 8.9 Resolution: | Keywords: CodeGen Operating System: Windows | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by AndreasK): The problem with mc is that we can get assembly with CPP directives in it: {{{ 8:52 PM AndreasK> bgamari: our generated assembly contains CPP directives? 8:55 PM <bgamari> no, but a TH splice may have added an assembler source file that does }}} We could (depending on the backend used) invoke gcc on the generated assembly just for CPP and the pass the result on to as/llvm-mc depending on the backend. {{{ AndreasK> bgamari: We could pipe assembly through the gcc CPP, and then pipe the result through as/llvm-mc depending on backend though right? 9:00 PM <bgamari> AndreasK, yes 9:00 PM we already have support for invoking the preprocessor 9:00 PM so really this is likely just a matter of plumbing }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16354#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16354: LLVM Backend generates invalid assembly. -------------------------------------+------------------------------------- Reporter: AndreasK | Owner: (none) Type: bug | Status: new Priority: high | Milestone: Component: Compiler (LLVM) | Version: 8.9 Resolution: | Keywords: CodeGen Operating System: Windows | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by AndreasK): * status: upstream => new Comment: Given that LLVM will likely keep things specific to their assembler when it suits them I don't think we can count on this being resolved through upstream changes. So I'm reopening this. Just needs someone to dive into the plumbing. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16354#comment:11 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
participants (1)
-
GHC