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From: Jim Wilson <jimw@sifive.com>
To: gdb-patches@sourceware.org
Cc: Kito Cheng <kito@andestech.com>
Subject: [PATCH 24/24] RISC-V sim: Fix divw and remw.
Date: Sat, 17 Apr 2021 10:58:31 -0700	[thread overview]
Message-ID: <20210417175831.16413-25-jimw@sifive.com> (raw)
In-Reply-To: <20210417175831.16413-1-jimw@sifive.com>

From: Kito Cheng <kito@andestech.com>

According to spec, result is -2^31 only when divisor is -1 AND dividend
is -2^31 for divw.
According to spec, result is 0 only when divisor is -1 AND dividend
is -2^31 for remw.

	sim/riscv/
	* sim-main.c (execute_m): New local dividend32_max.  Set it.  Use
	in cases MATCH_DIVW and MATCH_REMW.
---
 sim/riscv/sim-main.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/sim/riscv/sim-main.c b/sim/riscv/sim-main.c
index 3974f61..d92f756 100644
--- a/sim/riscv/sim-main.c
+++ b/sim/riscv/sim-main.c
@@ -2020,9 +2020,11 @@ execute_m (SIM_CPU *cpu, unsigned_word iw, const struct riscv_opcode *op)
   const char *rs1_name = riscv_gpr_names_abi[rs1];
   const char *rs2_name = riscv_gpr_names_abi[rs2];
   unsigned_word tmp, dividend_max;
+  signed_word dividend32_max;
   sim_cia pc = cpu->pc + 4;
 
   dividend_max = -((unsigned_word) 1 << (WITH_TARGET_WORD_BITSIZE - 1));
+  dividend32_max = INT32_MIN;
 
   switch (op->match)
     {
@@ -2041,7 +2043,8 @@ execute_m (SIM_CPU *cpu, unsigned_word iw, const struct riscv_opcode *op)
       TRACE_INSN (cpu, "divw %s, %s, %s;  // %s = %s / %s",
 		  rd_name, rs1_name, rs2_name, rd_name, rs1_name, rs2_name);
       RISCV_ASSERT_RV64 (cpu, "insn: %s", op->name);
-      if (EXTEND32 (cpu->regs[rs2]) == -1)
+      if (EXTEND32 (cpu->regs[rs1]) == dividend32_max
+	  && EXTEND32 (cpu->regs[rs2]) == -1)
 	tmp = 1 << 31;
       else if (EXTEND32 (cpu->regs[rs2]))
 	tmp = EXTEND32 (cpu->regs[rs1]) / EXTEND32 (cpu->regs[rs2]);
@@ -2122,7 +2125,8 @@ execute_m (SIM_CPU *cpu, unsigned_word iw, const struct riscv_opcode *op)
       TRACE_INSN (cpu, "remw %s, %s, %s;  // %s = %s %% %s",
 		  rd_name, rs1_name, rs2_name, rd_name, rs1_name, rs2_name);
       RISCV_ASSERT_RV64 (cpu, "insn: %s", op->name);
-      if (EXTEND32 (cpu->regs[rs2]) == -1)
+      if (EXTEND32 (cpu->regs[rs1]) == dividend32_max
+	  && EXTEND32 (cpu->regs[rs2]) == -1)
 	tmp = 0;
       else if (EXTEND32 (cpu->regs[rs2]))
 	tmp = EXTEND32 (cpu->regs[rs1]) % EXTEND32 (cpu->regs[rs2]);
-- 
2.7.4


  parent reply	other threads:[~2021-04-17 17:59 UTC|newest]

Thread overview: 70+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-17 17:58 [PATCH 00/24] RISC-V sim: Update from riscv-gnu-toolchain Jim Wilson
2021-04-17 17:58 ` [PATCH 01/24] RISC-V sim: Fix fence.i Jim Wilson
2021-04-17 20:36   ` Mike Frysinger via Gdb-patches
2021-04-17 17:58 ` [PATCH 02/24] RISC-V sim: Fix for jalr Jim Wilson
2021-04-19  3:41   ` Mike Frysinger via Gdb-patches
2021-04-17 17:58 ` [PATCH 03/24] RISC-V sim: Atomic fixes Jim Wilson
2021-04-19  3:56   ` Mike Frysinger via Gdb-patches
2021-04-21 23:00     ` Jim Wilson
2021-04-22  0:09       ` Mike Frysinger via Gdb-patches
2021-04-22  3:12         ` Jim Wilson
2021-04-17 17:58 ` [PATCH 04/24] RISC-V sim: More atomic fixes Jim Wilson
2021-04-19  3:57   ` Mike Frysinger via Gdb-patches
2021-04-17 17:58 ` [PATCH 05/24] RISC-V sim: Fix stack pointer alignment Jim Wilson
2021-04-19  3:58   ` Mike Frysinger via Gdb-patches
2021-04-21 22:39     ` Jim Wilson
2021-04-17 17:58 ` [PATCH 06/24] RISC-V: Add fp support Jim Wilson
2021-04-19  4:08   ` Mike Frysinger via Gdb-patches
2021-04-21 23:34     ` Jim Wilson
2021-04-17 17:58 ` [PATCH 07/24] RISC-V sim: Add link syscall support Jim Wilson
2021-04-19  4:09   ` Mike Frysinger via Gdb-patches
2021-04-21 23:36     ` Jim Wilson
2021-04-17 17:58 ` [PATCH 08/24] RISC-V sim: Add brk syscall Jim Wilson
2021-04-19  5:24   ` Mike Frysinger via Gdb-patches
2021-04-21 23:51     ` Jim Wilson
2021-04-17 17:58 ` [PATCH 09/24] RISC-V sim: Fix syscall fallback Jim Wilson
2021-04-21 23:38   ` Jim Wilson
2021-04-22  3:23     ` Mike Frysinger via Gdb-patches
2021-04-23 20:35       ` Jim Wilson
2021-04-17 17:58 ` [PATCH 10/24] RISC-V sim: Fix ebreak Jim Wilson
2021-04-19  4:20   ` Mike Frysinger via Gdb-patches
2021-04-17 17:58 ` [PATCH 11/24] RISC-V sim: Fix ebreak, part 2 Jim Wilson
2021-04-19  4:20   ` Mike Frysinger via Gdb-patches
2021-04-21 23:41     ` Jim Wilson
2021-04-17 17:58 ` [PATCH 12/24] RISC-V sim: Add compressed support Jim Wilson
2021-04-19  4:13   ` Mike Frysinger via Gdb-patches
2021-04-21 23:42     ` Jim Wilson
2021-04-17 17:58 ` [PATCH 13/24] RISC-V sim: Add gettimeofday Jim Wilson
2021-04-19  4:19   ` Mike Frysinger via Gdb-patches
2021-04-17 17:58 ` [PATCH 14/24] RISC-V sim: Add csrr*i instructions Jim Wilson
2021-04-19  4:26   ` Mike Frysinger via Gdb-patches
2021-04-17 17:58 ` [PATCH 15/24] RISC-V sim: Improve cycle and instret counts Jim Wilson
2021-04-19  4:25   ` Mike Frysinger via Gdb-patches
2021-04-22  2:26     ` Jim Wilson
2021-04-17 17:58 ` [PATCH 16/24] RISC-V sim: Check sbrk argument Jim Wilson
2021-04-19  5:33   ` Mike Frysinger via Gdb-patches
2021-04-17 17:58 ` [PATCH 17/24] RISC-V sim: Fix tracing typo Jim Wilson
2021-04-19  4:26   ` Mike Frysinger via Gdb-patches
2021-04-17 17:58 ` [PATCH 18/24] RISC-V sim: Improve branch tracing Jim Wilson
2021-04-19  4:27   ` Mike Frysinger via Gdb-patches
2021-04-17 17:58 ` [PATCH 19/24] RISC-V sim: Improve tracing for slt* instructions Jim Wilson
2021-04-19  4:27   ` Mike Frysinger via Gdb-patches
2021-04-17 17:58 ` [PATCH 20/24] RISC-V sim: Set brk to _end if possible Jim Wilson
2021-04-19  5:41   ` Mike Frysinger via Gdb-patches
2021-04-22  2:45     ` Jim Wilson
2021-04-17 17:58 ` [PATCH 21/24] RISC-V sim: Fix mingw builds Jim Wilson
2021-04-19  4:12   ` Mike Frysinger via Gdb-patches
2021-04-17 17:58 ` [PATCH 22/24] RISC-V sim: Support compressed FP instructions Jim Wilson
2021-04-19  4:27   ` Mike Frysinger via Gdb-patches
2021-04-17 17:58 ` [PATCH 23/24] RISC-V sim: Add zicsr support Jim Wilson
2021-04-19  5:13   ` Mike Frysinger via Gdb-patches
2021-04-17 17:58 ` Jim Wilson [this message]
2021-04-19  5:10   ` [PATCH 24/24] RISC-V sim: Fix divw and remw Mike Frysinger via Gdb-patches
2021-04-17 20:38 ` [PATCH 00/24] RISC-V sim: Update from riscv-gnu-toolchain Mike Frysinger via Gdb-patches
2021-04-19  2:33   ` Jim Wilson
2021-04-19  3:23     ` Mike Frysinger via Gdb-patches
2021-04-19  4:32       ` Jim Wilson
2021-04-19  3:42 ` Mike Frysinger via Gdb-patches
2021-04-19  4:37   ` Jim Wilson
2021-04-21 15:47 ` Andrew Burgess
2021-04-21 17:49   ` Andrew Burgess

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