From 1c37b30945073f34bbb685d2ac47ab01e0c93d45 Mon Sep 17 00:00:00 2001 From: Jaydeep Patil Date: Wed, 18 Oct 2023 17:37:59 +0100 Subject: [PATCH] sim/riscv: fix JALR instruction simulation Fix 32bit 'jalr rd,ra,imm' integer instruction, where RD was written before using it to calculate destination address. This commit also improves testutils.inc for riscv; make use of pushsection and popsection when adding things to .data, and setup the %gp global pointer register within the 'start' macro. Approved-By: Andrew Burgess --- sim/riscv/sim-main.c | 2 +- sim/testsuite/riscv/jalr.s | 22 ++++++++++++++++++++++ sim/testsuite/riscv/testutils.inc | 12 +++++++++--- 3 files changed, 32 insertions(+), 4 deletions(-) create mode 100644 sim/testsuite/riscv/jalr.s diff --git a/sim/riscv/sim-main.c b/sim/riscv/sim-main.c index 250791634a1..afdfcf50656 100644 --- a/sim/riscv/sim-main.c +++ b/sim/riscv/sim-main.c @@ -449,8 +449,8 @@ execute_i (SIM_CPU *cpu, unsigned_word iw, const struct riscv_opcode *op) break; case MATCH_JALR: TRACE_INSN (cpu, "jalr %s, %s, %" PRIiTW ";", rd_name, rs1_name, i_imm); - store_rd (cpu, rd, riscv_cpu->pc + 4); pc = riscv_cpu->regs[rs1] + i_imm; + store_rd (cpu, rd, riscv_cpu->pc + 4); TRACE_BRANCH (cpu, "to %#" PRIxTW, pc); break; diff --git a/sim/testsuite/riscv/jalr.s b/sim/testsuite/riscv/jalr.s new file mode 100644 index 00000000000..daccf4fb5a0 --- /dev/null +++ b/sim/testsuite/riscv/jalr.s @@ -0,0 +1,22 @@ +# Basic jalr tests. +# mach: riscv + +.include "testutils.inc" + + start + + # Load desination into register a0. + la a0, good_dest + + # Jump to the destination in a0. + jalr a0, a0, 0 + + # If we write destination into a0 before reading it in order + # to jump, we might end up here. +bad_dest: + fail + + # We should end up here. +good_dest: + pass + fail diff --git a/sim/testsuite/riscv/testutils.inc b/sim/testsuite/riscv/testutils.inc index b9680b9c22e..c5e09eb5ea3 100644 --- a/sim/testsuite/riscv/testutils.inc +++ b/sim/testsuite/riscv/testutils.inc @@ -21,8 +21,9 @@ # Trigger OS trap. ecall; exit 0; - .data + .pushsection .data 1: .asciz "pass\n" + .popsection .endm # MACRO: fail @@ -33,14 +34,15 @@ # Use stdout. li a0, 1; # Point to the string. - lla a1, 1f; + la a1, 1f; # Number of bytes to write. li a2, 5; # Trigger OS trap. ecall; exit 0; - .data + .pushsection .data 1: .asciz "fail\n" + .popsection .endm # MACRO: start @@ -49,4 +51,8 @@ .text .global _start _start: + .option push + .option norelax + lla gp, __global_pointer$ + .option pop .endm -- 2.30.2