For __builtin_ia32_vec_set_v16qi (a, -1, 2) with !flag_signed_char. it's transformed to __builtin_ia32_vec_set_v16qi (_4, 255, 2) in the gimple, and expanded to (const_int 255) in the rtl. But for immediate_operand, it expects (const_int 255) to be signed extended to (const_int -1). The mismatch caused an unrecognizable insn error.
expand_expr_real_1 generates (const_int 255) without considering the target mode. I guess it's on purpose, so I'll leave that alone and only change the expander in the backend. After applying convert_modes to (const_int 255), it's transformed to (const_int -1) which fix the issue. Bootstrapped and regtested x86_64-pc-linux-gnu{-m32,}. Ok for trunk(and backport to GCC-10/11/12 release branches)? gcc/ChangeLog: PR target/107863 * config/i386/i386-expand.cc (ix86_expand_vec_set_builtin): Convert op1 to target mode whenever mode mismatch. gcc/testsuite/ChangeLog: * gcc.target/i386/pr107863.c: New test. --- gcc/config/i386/i386-expand.cc | 2 +- gcc/testsuite/gcc.target/i386/pr107863.c | 8 ++++++++ 2 files changed, 9 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/gcc.target/i386/pr107863.c diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc index 0373c3614a4..c639ee3a9f7 100644 --- a/gcc/config/i386/i386-expand.cc +++ b/gcc/config/i386/i386-expand.cc @@ -12475,7 +12475,7 @@ ix86_expand_vec_set_builtin (tree exp) op1 = expand_expr (arg1, NULL_RTX, mode1, EXPAND_NORMAL); elt = get_element_number (TREE_TYPE (arg0), arg2); - if (GET_MODE (op1) != mode1 && GET_MODE (op1) != VOIDmode) + if (GET_MODE (op1) != mode1) op1 = convert_modes (mode1, GET_MODE (op1), op1, true); op0 = force_reg (tmode, op0); diff --git a/gcc/testsuite/gcc.target/i386/pr107863.c b/gcc/testsuite/gcc.target/i386/pr107863.c new file mode 100644 index 00000000000..99fd85d9765 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr107863.c @@ -0,0 +1,8 @@ +/* { dg-do compile } */ +/* { dg-options "-mavx2 -O" } */ + +typedef char v16qi __attribute__((vector_size(16))); + +v16qi foo(v16qi a){ + return __builtin_ia32_vec_set_v16qi (a, -1, 2); +} -- 2.27.0