Toolchain updates for bitmanip 1.0+0.93 support

For all toolchains:

- GCC 10.20
- binutils 2.35

For the bitmanip toolchains (rv32imcb):

- GCC and binutils with bitmanip 1.0+0.93 forks/patches
- LLVM 13.0.1-rc3. Supports most of bitmanip 0.93 with 1.0-compatible encodings.
  The only exception is the shift ones instructions (slo, sloi, sro, sroi).

README.md

@@ -49,25 +49,14 @@ How to do a release
    will be uploaded to
    [GitHub releases](https://github.com/lowRISC/lowrisc-toolchains/releases).
 
-How to generate the bitmanip patches
+How to generate the bitmanip patch
 ------------------------------------
 
-1. Generate the binutils patch:
-
-   ```
-   git clone https://github.com/riscv/riscv-binutils-gdb.git
-   cd riscv-binutils-gdb
-   git checkout riscv-bitmanip
-   # 612aac65 is our upstream baseline
-   git diff 612aac65 > $TOP/patches/binutils/git-612aac65/001-bitmanip.patch
-   ```
-
-2. Generate the GCC patch:
-
-   ```
-   git clone https://github.com/riscv/riscv-gcc.git
-   cd riscv-gcc
-   git checkout riscv-bitmanip
-   # 49f75e008c0 is our upstream baseline
-   git diff 49f75e008c0 > $TOP/patches/gcc/git-49f75e00/001-bitmanip.patch
-   ```
+```
+git clone https://github.com/riscv-collab/riscv-binutils-gdb.git
+cd riscv-binutils-gdb
+# checkout Pirmin's bitmanip 1.00+0.93 PR (https://github.com/riscv-collab/riscv-binutils-gdb/pull/267)
+gh pr checkout 267
+# 7c9dd840 (riscv-binutils-2.35-rvb) is our baseline
+git diff 7c9dd840 > $TOP/patches/lowrisc-toolchain-gcc-rv32imcb/binutils/git-7c9dd840/001-bitmanip.patch
+```

azure-pipelines.yml

@@ -57,9 +57,9 @@ jobs:
 
 - job: "Toolchains_RV32IMCB"
   displayName: "Toolchains targeting Ibex with 'Balanced' Bit-manipulation"
-  # These builds are using the 'Balanced' bit-manipulation subset identified in
-  # https://github.com/lowRISC/opentitan/issues/2708, and formatted for the
-  # correct versions as implemented by clang (B 0.92).
+  # These builds are using the ratified bitmanip extensions, version 1.0: Zba,
+  # Zbb, Zbc, and Zbs. For the current version of Clang we need to specify them
+  # as version 0.93, but they should be equivalent.
   pool:
     vmImage: "ubuntu-20.04"
   container: lowrisc/lowrisc-base-centos6:latest
@@ -73,31 +73,12 @@ jobs:
     displayName: "Prepare toolchain destination directory"
 
   - bash: |
-      # HACK: GCC does not allow you to compile with just a subset of the B
-      # extension using `-march=`, but it does assemble separately.
-      #
-      # So, we pass a more acceptable `-march=` to the assembler with `-Wa`.
-      #
-      # However, gcc will emit an assembly directive describing the arch it
-      # wanted when it compiled, which the assembler will use in spite of the
-      # `-march=` flag. So, we have to turn this off, using
-      # `-mno-riscv-attribute`.
-      #
-      # The end result is: The compiler will not introduce B extension
-      # instructions when compiling, but the assembler will understand them, so
-      # they can be used in inline assembly.
-      #
-      # If you update the patches in `patches/lowrisc-toolchain-gcc-rv32imcb`,
-      # you will need to revalidate that this behaviour works. A good testcase
-      # is a file with a `pcnt` instruction in inline assembly.
-      #
       ./build-gcc-with-args.sh \
         "lowrisc-toolchain-gcc-rv32imcb" \
         "riscv32-unknown-elf" \
         "/tools/riscv" \
-        "-march=rv32imc" "-mabi=ilp32" "-mcmodel=medany" \
-        "-Wa,-march=rv32imczbb0p92_zbf0p92_zbs0p92_zbt0p92" \
-        "-mno-riscv-attribute"
+        "-march=rv32imc_zba_zbb_zbc_zbs" \
+        "-mabi=ilp32" "-mcmodel=medany"
     displayName: 'Build GCC toolchain'
     env:
       ARTIFACT_STAGING_DIR: $(Build.ArtifactStagingDirectory)
@@ -108,7 +89,7 @@ jobs:
         "lowrisc-toolchain-rv32imcb" \
         "riscv32-unknown-elf" \
         "/tools/riscv" \
-        "-march=rv32imczbb0p92_zbf0p92_zbs0p92_zbt0p92" \
+        "-march=rv32imc_zba0p93_zbb0p93_zbc0p93_zbs0p93" \
         "-mabi=ilp32" "-mcmodel=medany" "-menable-experimental-extensions"
     displayName: "Build Clang toolchain"
     env:

build-clang-with-args.sh

@@ -42,6 +42,12 @@ build_top_dir="${PWD}"
 # shellcheck source=sw-versions.sh
 source "${build_top_dir}/sw-versions.sh"
 
+if [[ "${toolchain_name}" == *-rv32imcb ]]; then
+  llvm_version="${LLVM_BITMANIP_VERSION}"
+else
+  llvm_version="${LLVM_VERSION}"
+fi
+
 tag_name="${RELEASE_TAG:-HEAD}"
 toolchain_full_name="${toolchain_name}-${tag_name}"
 
@@ -55,7 +61,7 @@ if [ ! -d "${llvm_dir}" ]; then
 fi
 cd "${llvm_dir}"
 git fetch origin
-git checkout --force "${LLVM_VERSION}"
+git checkout --force "${llvm_version}"
 
 # Clang Symlinks
 clang_links_to_create="clang++"
@@ -155,7 +161,7 @@ lowRISC toolchain version: ${tag_name}
 
 Clang version:
   ${clang_version_string}
-  (git: ${LLVM_URL} ${LLVM_VERSION})
+  (git: ${LLVM_URL} ${llvm_version})
 
 GCC version:
   ${gcc_version_string}
@@ -177,7 +183,7 @@ tee "${toolchain_dest}/buildinfo.json" <<BUILDINFO_JSON
   "version": "${tag_name}",
   "clang_version": "${clang_version_string}",
   "clang_url": "${LLVM_URL}",
-  "clang_git": "${LLVM_VERSION}",
+  "clang_git": "${llvm_version}",
   "gcc_version": "${gcc_version_string}",
   "crosstool-ng_version": "${ct_ng_version_string}",
   "crosstool-ng_url": "${CROSSTOOL_NG_URL}",

lowrisc-toolchain-gcc-rv32imc.config

@@ -7,10 +7,6 @@ CT_ARCH_RISCV=y
 # are built with. It should specify the minimum RISC-V extensions that need to
 # be implemented by any processor that this toolchain will compile programs for.
 #
-# 2020-03-26: We have added B extension (v0.92) support to the compiler using
-#             experimental patches, but we still want to support Ibex without
-#             the B extension, so this remains "rv32imc".
-#
 CT_ARCH_ARCH="rv32imc"
 
 # CT_ARCH_ABI controls the specific ABI that the toolchain's libraries are built
@@ -48,5 +44,17 @@ CT_PREFIX_DIR="/tools/riscv"
 # Don't chmod the CT_PREFIX_DIR read-only after the install.
 # CT_PREFIX_DIR_RO is not set
 
+# Binutils 2.35 (tag binutils-2_35, commit 2cb5c79dad3)
+CT_BINUTILS_SRC_DEVEL=y
+CT_BINUTILS_DEVEL_VCS_git=y
+CT_BINUTILS_DEVEL_URL="https://github.com/bminor/binutils-gdb.git"
+CT_BINUTILS_DEVEL_REVISION="2cb5c79dad39dd438fb0f7372ac04cf5aa2a7db7"
+
+# GCC 10.2.0 (tag releases/gcc-10.2.0, commit ee5c3db6c5b)
+CT_GCC_SRC_DEVEL=y
+CT_GCC_DEVEL_VCS_git=y
+CT_GCC_DEVEL_URL="https://gcc.gnu.org/git/gcc.git"
+CT_GCC_DEVEL_REVISION="ee5c3db6c5b2c3332912fb4c9cfa2864569ebd9a"
+
 # The build script appends a definition of CT_LOCAL_PATCH_DIR down here, that
 # points to the repo's patch directory.

lowrisc-toolchain-gcc-rv32imcb.config

@@ -7,9 +7,19 @@ CT_ARCH_RISCV=y
 # are built with. It should specify the minimum RISC-V extensions that need to
 # be implemented by any processor that this toolchain will compile programs for.
 #
-# 2020-03-26: We have added B extension (v0.92) support to the compiler using
-#             experimental patches, but we still want to support Ibex without
-#             the B extension, so this remains "rv32imc".
+# 2022-01-13: We can now generally assume that Ibex supports bitmanip, so we can
+#             compile the toolchain libraries with bitmanip 1.0 support.
+#
+#               N.B. OpenTitan still requires support for Ibex without bitmanip
+#               (in the English Breakfast toplevel design) but OpenTitan is
+#               freestanding, so it shouldn't use these libraries.
+#
+#             Unfortunately, when we tried to enable the ratified bitmanip
+#             subset here by specifying `CT_ARCH_ARCH=rv32imc_zba_zbb_zbc_zbs`
+#             the toolchain failed to compile, saying that `rol` (from Zbb)
+#             wasn't a recognized instruction. Until this is solved we don't
+#             compile the libraries with bitmanip. This doesn't really matter
+#             for our current use cases.
 #
 CT_ARCH_ARCH="rv32imc"
 
@@ -48,17 +58,20 @@ CT_PREFIX_DIR="/tools/riscv"
 # Don't chmod the CT_PREFIX_DIR read-only after the install.
 # CT_PREFIX_DIR_RO is not set
 
-# We apply the binutils bitmanip patches on top of git commit 612aac65
+# Binutils 2.35, RISC-V bitmanip fork (branch riscv-binutils-2.35-rvb,
+# commit 7c9dd840fb from 2021-03-10).
+# A bitmanip 1.0+0.93 patch will be applied on top.
 CT_BINUTILS_SRC_DEVEL=y
 CT_BINUTILS_DEVEL_VCS_git=y
-CT_BINUTILS_DEVEL_URL="https://github.com/bminor/binutils-gdb.git"
-CT_BINUTILS_DEVEL_REVISION="612aac65e690387c963c34a31dd1fb138d88a45c"
+CT_BINUTILS_DEVEL_URL="https://github.com/riscv-collab/riscv-binutils-gdb.git"
+CT_BINUTILS_DEVEL_REVISION="7c9dd840fbb6a1171a51feb08afb859288615137"
 
-# We apply the gcc bitmanip patches on top of git commit 49f75e008c0
+# GCC 10.2.0, RISC-V bitmanip fork (branch riscv-gcc-10.2.0-rvb,
+# commit 73055647d33 from 2021-07-09)
 CT_GCC_SRC_DEVEL=y
 CT_GCC_DEVEL_VCS_git=y
-CT_GCC_DEVEL_URL="https://github.com/riscv/riscv-gcc.git"
-CT_GCC_DEVEL_REVISION="49f75e008c0809eb3c74a163297b4aa8925c9f1c"
+CT_GCC_DEVEL_URL="https://github.com/riscv-collab/riscv-gcc"
+CT_GCC_DEVEL_REVISION="73055647d33c0b63a3125c372019d1dac0f8ac34"
 
 # The build script appends a definition of CT_LOCAL_PATCH_DIR down here, that
 # points to the repo's patch directory.

lowrisc-toolchain-gcc-rv64imac.config

@@ -46,5 +46,17 @@ CT_PREFIX_DIR="/tools/riscv"
 # Don't chmod the CT_PREFIX_DIR read-only after the install.
 # CT_PREFIX_DIR_RO is not set
 
+# Binutils 2.35 (tag binutils-2_35, commit 2cb5c79dad3)
+CT_BINUTILS_SRC_DEVEL=y
+CT_BINUTILS_DEVEL_VCS_git=y
+CT_BINUTILS_DEVEL_URL="https://github.com/bminor/binutils-gdb.git"
+CT_BINUTILS_DEVEL_REVISION="2cb5c79dad39dd438fb0f7372ac04cf5aa2a7db7"
+
+# GCC 10.2.0 (tag releases/gcc-10.2.0, commit ee5c3db6c5b)
+CT_GCC_SRC_DEVEL=y
+CT_GCC_DEVEL_VCS_git=y
+CT_GCC_DEVEL_URL="https://gcc.gnu.org/git/gcc.git"
+CT_GCC_DEVEL_REVISION="ee5c3db6c5b2c3332912fb4c9cfa2864569ebd9a"
+
 # The build script appends a definition of CT_LOCAL_PATCH_DIR down here, that
 # points to the repo's patch directory.