[v9,11/24] target/arm: Hoist computation of TBFLAG_A32.VFPEN
diff mbox series

Message ID 20191023150057.25731-12-richard.henderson@linaro.org
State New
Headers show
Series
  • target/arm: Reduce overhead of cpu_get_tb_cpu_state
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Commit Message

Richard Henderson Oct. 23, 2019, 3 p.m. UTC
There are 3 conditions that each enable this flag.  M-profile always
enables; A-profile with EL1 as AA64 always enables.  Both of these
conditions can easily be cached.  The final condition relies on the
FPEXC register which we are not prepared to cache.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/cpu.h    |  2 +-
 target/arm/helper.c | 14 ++++++++++----
 2 files changed, 11 insertions(+), 5 deletions(-)

Patch
diff mbox series

diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 4d961474ce..9909ff89d4 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -3192,7 +3192,7 @@  FIELD(TBFLAG_A32, XSCALE_CPAR, 4, 2)
  * the same thing as the current security state of the processor!
  */
 FIELD(TBFLAG_A32, NS, 6, 1)
-FIELD(TBFLAG_A32, VFPEN, 7, 1)          /* Not cached. */
+FIELD(TBFLAG_A32, VFPEN, 7, 1)          /* Partially cached, minus FPEXC. */
 FIELD(TBFLAG_A32, CONDEXEC, 8, 8)       /* Not cached. */
 FIELD(TBFLAG_A32, SCTLR_B, 16, 1)
 /* For M profile only, set if FPCCR.LSPACT is set */
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 398e5f5d6d..89aa6fd933 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -11088,6 +11088,9 @@  static uint32_t rebuild_hflags_m32(CPUARMState *env, int fp_el,
 {
     uint32_t flags = 0;
 
+    /* v8M always enables the fpu.  */
+    flags = FIELD_DP32(flags, TBFLAG_A32, VFPEN, 1);
+
     if (arm_v7m_is_handler_mode(env)) {
         flags = FIELD_DP32(flags, TBFLAG_A32, HANDLER, 1);
     }
@@ -11119,6 +11122,10 @@  static uint32_t rebuild_hflags_a32(CPUARMState *env, int fp_el,
                                    ARMMMUIdx mmu_idx)
 {
     uint32_t flags = rebuild_hflags_aprofile(env);
+
+    if (arm_el_is_aa64(env, 1)) {
+        flags = FIELD_DP32(flags, TBFLAG_A32, VFPEN, 1);
+    }
     return rebuild_hflags_common_32(env, fp_el, mmu_idx, flags);
 }
 
@@ -11250,14 +11257,13 @@  void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc,
                 flags = FIELD_DP32(flags, TBFLAG_A32, VECSTRIDE,
                                    env->vfp.vec_stride);
             }
+            if (env->vfp.xregs[ARM_VFP_FPEXC] & (1 << 30)) {
+                flags = FIELD_DP32(flags, TBFLAG_A32, VFPEN, 1);
+            }
         }
 
         flags = FIELD_DP32(flags, TBFLAG_A32, THUMB, env->thumb);
         flags = FIELD_DP32(flags, TBFLAG_A32, CONDEXEC, env->condexec_bits);
-        if (env->vfp.xregs[ARM_VFP_FPEXC] & (1 << 30)
-            || arm_el_is_aa64(env, 1) || arm_feature(env, ARM_FEATURE_M)) {
-            flags = FIELD_DP32(flags, TBFLAG_A32, VFPEN, 1);
-        }
         pstate_for_ss = env->uncached_cpsr;
     }