Date: Fri, 21 Apr 2017 17:03:48 +0000 (UTC) From: Dimitry Andric <dim@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org Subject: svn commit: r317261 - stable/11/contrib/llvm/lib/Target/X86 Message-ID: <201704211703.v3LH3mVL098689@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: dim Date: Fri Apr 21 17:03:48 2017 New Revision: 317261 URL: https://svnweb.freebsd.org/changeset/base/317261 Log: MFC r316989: Pull in r300404 from upstream llvm trunk (by me): Use correct registers for "A" inline asm constraint Summary: In PR32594, inline assembly using the 'A' constraint on x86_64 causes llvm to crash with a "Cannot select" stack trace. This is because `X86TargetLowering::getRegForInlineAsmConstraint` hardcodes that 'A' means the EAX and EDX registers. However, on x86_64 it means the RAX and RDX registers, and on 16-bit x86 (ia16?) it means the old AX and DX registers. Add new register classes in `X86RegisterInfo.td` to support these cases, and amend the logic in `getRegForInlineAsmConstraint` to cope with different subtargets. Also add a test case, derived from PR32594. Reviewers: craig.topper, qcolombet, RKSimon, ab Reviewed By: ab Subscribers: ab, emaste, royger, llvm-commits Differential Revision: https://reviews.llvm.org/D31902 This should fix crashes when using the 'A' constraint on amd64, for example as it is being used in Xen. Reported by: royger MFC r317079: Pull in r300429 from upstream llvm trunk (by Benjamin Kramer): [X86] Remove special handling for 16 bit for A asm constraints. Our 16 bit support is assembler-only + the terrible hack that is .code16gcc. Simply using 32 bit registers does the right thing for the latter. Fixes PR32681. This fixes some cases of assembling 16 bit code (i.e. SeaBIOS) that uses the 'A' inline asm constraint, after r316989. Modified: stable/11/contrib/llvm/lib/Target/X86/X86ISelLowering.cpp stable/11/contrib/llvm/lib/Target/X86/X86RegisterInfo.td Directory Properties: stable/11/ (props changed) Modified: stable/11/contrib/llvm/lib/Target/X86/X86ISelLowering.cpp ============================================================================== --- stable/11/contrib/llvm/lib/Target/X86/X86ISelLowering.cpp Fri Apr 21 16:47:57 2017 (r317260) +++ stable/11/contrib/llvm/lib/Target/X86/X86ISelLowering.cpp Fri Apr 21 17:03:48 2017 (r317261) @@ -34717,10 +34717,17 @@ X86TargetLowering::getRegForInlineAsmCon return Res; } - // 'A' means EAX + EDX. + // 'A' means [ER]AX + [ER]DX. if (Constraint == "A") { - Res.first = X86::EAX; - Res.second = &X86::GR32_ADRegClass; + if (Subtarget.is64Bit()) { + Res.first = X86::RAX; + Res.second = &X86::GR64_ADRegClass; + } else { + assert((Subtarget.is32Bit() || Subtarget.is16Bit()) && + "Expecting 64, 32 or 16 bit subtarget"); + Res.first = X86::EAX; + Res.second = &X86::GR32_ADRegClass; + } return Res; } return Res; Modified: stable/11/contrib/llvm/lib/Target/X86/X86RegisterInfo.td ============================================================================== --- stable/11/contrib/llvm/lib/Target/X86/X86RegisterInfo.td Fri Apr 21 16:47:57 2017 (r317260) +++ stable/11/contrib/llvm/lib/Target/X86/X86RegisterInfo.td Fri Apr 21 17:03:48 2017 (r317261) @@ -437,8 +437,9 @@ def LOW32_ADDR_ACCESS : RegisterClass<"X def LOW32_ADDR_ACCESS_RBP : RegisterClass<"X86", [i32], 32, (add LOW32_ADDR_ACCESS, RBP)>; -// A class to support the 'A' assembler constraint: EAX then EDX. +// A class to support the 'A' assembler constraint: [ER]AX then [ER]DX. def GR32_AD : RegisterClass<"X86", [i32], 32, (add EAX, EDX)>; +def GR64_AD : RegisterClass<"X86", [i64], 64, (add RAX, RDX)>; // Scalar SSE2 floating point registers. def FR32 : RegisterClass<"X86", [f32], 32, (sequence "XMM%u", 0, 15)>;
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201704211703.v3LH3mVL098689>