From 3399f1b3030c3419859f1230bc66a981154d176d Mon Sep 17 00:00:00 2001 From: Jim Wilson Date: Mon, 22 Oct 2018 14:11:55 -0700 Subject: [PATCH] RISC-V: NaN-box FP values smaller than an FP register. The hardware requires that values in FP registers be NaN-boxed, so we must extend them with 1's instead of 0's as we do for integer values. gdb/ * riscv-tdep.c (riscv_push_dummy_call) : Check for value in FP reg smaller than FP reg size, and fill with -1 instead of 0. --- gdb/ChangeLog | 3 +++ gdb/riscv-tdep.c | 14 ++++++++++++-- 2 files changed, 15 insertions(+), 2 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 9055a3a57f..a30d72b27f 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,8 @@ 2018-10-22 Jim Wilson + * riscv-tdep.c (riscv_push_dummy_call) : Check for value in + FP reg smaller than FP reg size, and fill with -1 instead of 0. + * riscv-tdep.c (riscv_fpreg_d_type, riscv_fpreg_q_type): New. (riscv_register_type): Use them. (riscv_print_one_register_info): Handle union of floats same as float. diff --git a/gdb/riscv-tdep.c b/gdb/riscv-tdep.c index 1a75788489..dd80f95c98 100644 --- a/gdb/riscv-tdep.c +++ b/gdb/riscv-tdep.c @@ -2408,7 +2408,12 @@ riscv_push_dummy_call (struct gdbarch *gdbarch, gdb_byte tmp [sizeof (ULONGEST)]; gdb_assert (info->argloc[0].c_length <= info->length); - memset (tmp, 0, sizeof (tmp)); + /* FP values in FP registers must be NaN-boxed. */ + if (riscv_is_fp_regno_p (info->argloc[0].loc_data.regno) + && info->argloc[0].c_length < call_info.flen) + memset (tmp, -1, sizeof (tmp)); + else + memset (tmp, 0, sizeof (tmp)); memcpy (tmp, info->contents, info->argloc[0].c_length); regcache->cooked_write (info->argloc[0].loc_data.regno, tmp); second_arg_length = @@ -2447,7 +2452,12 @@ riscv_push_dummy_call (struct gdbarch *gdbarch, gdb_assert ((riscv_is_fp_regno_p (info->argloc[1].loc_data.regno) && second_arg_length <= call_info.flen) || second_arg_length <= call_info.xlen); - memset (tmp, 0, sizeof (tmp)); + /* FP values in FP registers must be NaN-boxed. */ + if (riscv_is_fp_regno_p (info->argloc[1].loc_data.regno) + && second_arg_length < call_info.flen) + memset (tmp, -1, sizeof (tmp)); + else + memset (tmp, 0, sizeof (tmp)); memcpy (tmp, second_arg_data, second_arg_length); regcache->cooked_write (info->argloc[1].loc_data.regno, tmp); } -- 2.34.1