https://github.com/Ris-Bali created https://github.com/llvm/llvm-project/pull/212474
The external assembler path (-fno-integrated-as, which invokes llvm-mc) only forwarded -mcpu and -mhvx-ieee-fp, so target features such as HVX, HVX length, HVX qfloat, and long-calls never reached the assembler. As a result, HVX-using code that compiled fine with the integrated assembler failed to assemble with the external one. Compute the features with hexagon::getHexagonTargetFeatures(); the same helper used by the compiler and integrated assembler and forward them to llvm-mc via -mattr=, bringing the external assembler path to parity so behavior is consistent regardless of which assembler is selected. Fixes #212471 >From f0ded42ae23684d1d2e0bedbe1f8b35aad747e3b Mon Sep 17 00:00:00 2001 From: Rishabh Bali <[email protected]> Date: Tue, 28 Jul 2026 17:08:35 +0530 Subject: [PATCH] [Hexagon] Forward target features to the external assembler The external assembler path (-fno-integrated-as, which invokes llvm-mc) only forwarded -mcpu and -mhvx-ieee-fp, so target features such as HVX, HVX length, HVX qfloat, and long-calls never reached the assembler. As a result, HVX-using code that compiled fine with the integrated assembler failed to assemble with the external one. Compute the features with hexagon::getHexagonTargetFeatures(); the same helper used by the compiler and integrated assembler and forward them to llvm-mc via -mattr=, bringing the external assembler path to parity so behavior is consistent regardless of which assembler is selected. Signed-off-by: Rishabh Bali <[email protected]> --- clang/lib/Driver/ToolChains/Hexagon.cpp | 16 +++++-- .../Driver/hexagon-external-as-features.c | 46 +++++++++++++++++++ 2 files changed, 57 insertions(+), 5 deletions(-) create mode 100644 clang/test/Driver/hexagon-external-as-features.c diff --git a/clang/lib/Driver/ToolChains/Hexagon.cpp b/clang/lib/Driver/ToolChains/Hexagon.cpp index 2ddc15ddbd818..41e5972361c14 100644 --- a/clang/lib/Driver/ToolChains/Hexagon.cpp +++ b/clang/lib/Driver/ToolChains/Hexagon.cpp @@ -14,6 +14,7 @@ #include "clang/Driver/MultilibBuilder.h" #include "clang/Driver/SanitizerArgs.h" #include "clang/Options/Options.h" +#include "llvm/ADT/StringExtras.h" #include "llvm/Option/ArgList.h" #include "llvm/Support/FileSystem.h" #include "llvm/Support/Path.h" @@ -228,11 +229,16 @@ void hexagon::Assembler::ConstructJob(Compilation &C, const JobAction &JA, CmdArgs.push_back("-fsyntax-only"); } - if (Arg *A = Args.getLastArg(options::OPT_mhexagon_hvx_ieee_fp, - options::OPT_mno_hexagon_hvx_ieee_fp)) { - if (A->getOption().matches(options::OPT_mhexagon_hvx_ieee_fp)) - CmdArgs.push_back("-mhvx-ieee-fp"); - } + // Forward the target features (e.g. HVX, HVX length, HVX qfloat/ieee-fp) to + // the external assembler so that its behavior matches the integrated + // assembler. getHexagonTargetFeatures() computes the same feature list that + // the compiler and integrated assembler use, and llvm-mc consumes it via + // -mattr=. + std::vector<StringRef> Features; + hexagon::getHexagonTargetFeatures(D, HTC.getTriple(), Args, Features); + if (!Features.empty()) + CmdArgs.push_back( + Args.MakeArgString("-mattr=" + llvm::join(Features, ","))); if (auto G = toolchains::HexagonToolChain::getSmallDataThreshold(Args)) { CmdArgs.push_back(Args.MakeArgString("-gpsize=" + Twine(*G))); diff --git a/clang/test/Driver/hexagon-external-as-features.c b/clang/test/Driver/hexagon-external-as-features.c new file mode 100644 index 0000000000000..1bc78ef011473 --- /dev/null +++ b/clang/test/Driver/hexagon-external-as-features.c @@ -0,0 +1,46 @@ +// ----------------------------------------------------------------------------- +// Tests that target features are forwarded to the external assembler +// (llvm-mc) via -mattr= when -fno-integrated-as is used, so that the +// external assembler path is on par with the integrated assembler. +// ----------------------------------------------------------------------------- + +// Baseline: no HVX means no HVX features in -mattr=. +// RUN: %clang -### -c %s --target=hexagon-unknown-elf -fno-integrated-as \ +// RUN: -mcpu=hexagonv79 2>&1 | FileCheck -check-prefix=CHECK-NOHVX %s +// CHECK-NOHVX: llvm-mc +// CHECK-NOHVX-SAME: "-mcpu=hexagonv79" +// CHECK-NOHVX-NOT: "+hvx + +// -mhvx enables HVX for the external assembler. +// RUN: %clang -### -c %s --target=hexagon-unknown-elf -fno-integrated-as \ +// RUN: -mcpu=hexagonv79 -mhvx 2>&1 | FileCheck -check-prefix=CHECK-HVX %s +// CHECK-HVX: llvm-mc +// CHECK-HVX-SAME: "-mcpu=hexagonv79" +// CHECK-HVX-SAME: "-mattr={{[^"]*}}+hvxv79 + +// -mhvx= selects an explicit HVX version. +// RUN: %clang -### -c %s --target=hexagon-unknown-elf -fno-integrated-as \ +// RUN: -mcpu=hexagonv79 -mhvx=v68 2>&1 | FileCheck -check-prefix=CHECK-HVXV68 %s +// CHECK-HVXV68: llvm-mc +// CHECK-HVXV68-SAME: "-mattr={{[^"]*}}+hvxv68 + +// -mhvx-length= is forwarded. +// RUN: %clang -### -c %s --target=hexagon-unknown-elf -fno-integrated-as \ +// RUN: -mcpu=hexagonv79 -mhvx -mhvx-length=128b 2>&1 \ +// RUN: | FileCheck -check-prefix=CHECK-HVXLEN %s +// CHECK-HVXLEN: llvm-mc +// CHECK-HVXLEN-SAME: "-mattr={{[^"]*}}+hvx-length128b + +// -mhvx-qfloat is forwarded. +// RUN: %clang -### -c %s --target=hexagon-unknown-elf -fno-integrated-as \ +// RUN: -mcpu=hexagonv79 -mhvx -mhvx-qfloat 2>&1 \ +// RUN: | FileCheck -check-prefix=CHECK-HVXQFLOAT %s +// CHECK-HVXQFLOAT: llvm-mc +// CHECK-HVXQFLOAT-SAME: "-mattr={{[^"]*}}+hvx-qfloat + +// -mhvx-ieee-fp is forwarded (previously the only HVX flag handled here). +// RUN: %clang -### -c %s --target=hexagon-unknown-elf -fno-integrated-as \ +// RUN: -mcpu=hexagonv73 -mhvx -mhvx-ieee-fp 2>&1 \ +// RUN: | FileCheck -check-prefix=CHECK-HVXIEEE %s +// CHECK-HVXIEEE: llvm-mc +// CHECK-HVXIEEE-SAME: "-mattr={{[^"]*}}+hvx-ieee-fp _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
