According to Zc-1.0.4-3.pdf from https://github.com/riscvarchive/riscv-code-size-reduction/releases/tag/v1.0.4-3 The rule is that: 1. C always implies Zca 2. C+F implies Zcf (RV32 only) 3. C+D implies Zcd Patch 2 handles this implication.
Without Patch 1, Patch 2 triggers an ICE when compiling gcc/testsuite/gcc.target/riscv/rvv/base/cpymem-1.c with -march=rv32imafcv. The ICE is due to failure of gcc_assert (check_implied_ext ()) in riscv_subset_list::finalize (). check_implied_ext checks if ALL implied extensions have been added after handle_implied_ext. In rv32imafcv case, handle_implied_ext first handles 'c'. As there's no 'd' in subset list, zcd hasn't been added. Then handle_implied_ext handles 'v'. 'v' implies 'zve64d', and 'zve64d' implies 'd', so 'd' has been added into subset list. However, after handle_implied_ext, check_implied_ext finds 'c' and 'd' both available in subset list, but 'zcd' is not here, causing assert failure. Patch 1 sovles the assert failure by calling handle_implied_ext repeatly until there's no new subset added into the subset list. This patch series also helps to expose the conflict between c+d and zcmp/zcmt. Regession tested rv64gc with no new failures. Fei Gao (2): [RISC-V] add impied extension repeatly until stable [RISC-V] c impies zca, and conditionally zcf & zcd gcc/common/config/riscv/riscv-common.cc | 26 ++++++++++++++++--- gcc/config/riscv/riscv-subset.h | 3 +++ gcc/testsuite/gcc.target/riscv/arch-39.c | 7 +++++ gcc/testsuite/gcc.target/riscv/arch-40.c | 7 +++++ gcc/testsuite/gcc.target/riscv/attribute-15.c | 2 +- gcc/testsuite/gcc.target/riscv/attribute-18.c | 2 +- gcc/testsuite/gcc.target/riscv/pr110696.c | 2 +- .../riscv/rvv/base/abi-callee-saved-1-zcmp.c | 2 +- .../riscv/rvv/base/abi-callee-saved-2-zcmp.c | 2 +- .../gcc.target/riscv/rvv/base/pr114352-1.c | 4 +-- .../gcc.target/riscv/rvv/base/pr114352-3.c | 8 +++--- 11 files changed, 51 insertions(+), 14 deletions(-) create mode 100644 gcc/testsuite/gcc.target/riscv/arch-39.c create mode 100644 gcc/testsuite/gcc.target/riscv/arch-40.c -- 2.17.1
