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[PULL 05/23] target/arm: Correct store of FPSCR value via FPCXT_S
From: |
Peter Maydell |
Subject: |
[PULL 05/23] target/arm: Correct store of FPSCR value via FPCXT_S |
Date: |
Fri, 8 Jan 2021 15:36:03 +0000 |
In commit 64f863baeedc8659 we implemented the v8.1M FPCXT_S register,
but we got the write behaviour wrong. On read, this register reads
bits [27:0] of FPSCR plus the CONTROL.SFPA bit. On write, it doesn't
just write back those bits -- it writes a value to the whole FPSCR,
whose upper 4 bits are zeroes.
We also incorrectly implemented the write-to-FPSCR as a simple store
to vfp.xregs; this skips the "update the softfloat flags" part of
the vfp_set_fpscr helper so the value would read back correctly but
not actually take effect.
Fix both of these things by doing a complete write to the FPSCR
using the helper function.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201210201433.26262-3-peter.maydell@linaro.org
---
target/arm/translate-vfp.c.inc | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/target/arm/translate-vfp.c.inc b/target/arm/translate-vfp.c.inc
index 0db936084bd..8b4cfd68cad 100644
--- a/target/arm/translate-vfp.c.inc
+++ b/target/arm/translate-vfp.c.inc
@@ -723,8 +723,11 @@ static bool gen_M_fp_sysreg_write(DisasContext *s, int
regno,
}
case ARM_VFP_FPCXT_S:
{
- TCGv_i32 sfpa, control, fpscr;
- /* Set FPSCR[27:0] and CONTROL.SFPA from value */
+ TCGv_i32 sfpa, control;
+ /*
+ * Set FPSCR and CONTROL.SFPA from value; the new FPSCR takes
+ * bits [27:0] from value and zeroes bits [31:28].
+ */
tmp = loadfn(s, opaque);
sfpa = tcg_temp_new_i32();
tcg_gen_shri_i32(sfpa, tmp, 31);
@@ -732,11 +735,8 @@ static bool gen_M_fp_sysreg_write(DisasContext *s, int
regno,
tcg_gen_deposit_i32(control, control, sfpa,
R_V7M_CONTROL_SFPA_SHIFT, 1);
store_cpu_field(control, v7m.control[M_REG_S]);
- fpscr = load_cpu_field(vfp.xregs[ARM_VFP_FPSCR]);
- tcg_gen_andi_i32(fpscr, fpscr, FPCR_NZCV_MASK);
tcg_gen_andi_i32(tmp, tmp, ~FPCR_NZCV_MASK);
- tcg_gen_or_i32(fpscr, fpscr, tmp);
- store_cpu_field(fpscr, vfp.xregs[ARM_VFP_FPSCR]);
+ gen_helper_vfp_set_fpscr(cpu_env, tmp);
tcg_temp_free_i32(tmp);
tcg_temp_free_i32(sfpa);
break;
--
2.20.1
- [PULL 00/23] target-arm queue, Peter Maydell, 2021/01/08
- [PULL 01/23] intc/arm_gic: Fix gic_irq_signaling_enabled() for vCPUs, Peter Maydell, 2021/01/08
- [PULL 02/23] hw/arm/virt: Remove virt machine state 'smp_cpus', Peter Maydell, 2021/01/08
- [PULL 03/23] target/arm: Fix MTE0_ACTIVE, Peter Maydell, 2021/01/08
- [PULL 04/23] hw/intc/armv7m_nvic: Correct handling of CCR.BFHFNMIGN, Peter Maydell, 2021/01/08
- [PULL 05/23] target/arm: Correct store of FPSCR value via FPCXT_S,
Peter Maydell <=
- [PULL 06/23] target/arm: Implement FPCXT_NS fp system register, Peter Maydell, 2021/01/08
- [PULL 07/23] target/arm: Implement Cortex-M55 model, Peter Maydell, 2021/01/08
- [PULL 08/23] hw/arm/highbank: Drop dead KVM support code, Peter Maydell, 2021/01/08
- [PULL 10/23] scripts/coccinelle: New script to remove unnecessary timer_del() calls, Peter Maydell, 2021/01/08
- [PULL 09/23] util/qemu-timer: Make timer_free() imply timer_del(), Peter Maydell, 2021/01/08
- [PULL 12/23] target/arm: Remove timer_del()/timer_deinit() before timer_free(), Peter Maydell, 2021/01/08
- [PULL 11/23] Remove superfluous timer_del() calls, Peter Maydell, 2021/01/08
- [PULL 14/23] allwinner-a10-pit: Use ptimer_free() in the finalize function to avoid memleaks, Peter Maydell, 2021/01/08
- [PULL 16/23] exynos4210_pwm: Use ptimer_free() in the finalize function to avoid memleaks, Peter Maydell, 2021/01/08
- [PULL 13/23] digic-timer: Use ptimer_free() in the finalize function to avoid memleaks, Peter Maydell, 2021/01/08