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-rw-r--r--target/arm/cpu.h41
-rw-r--r--target/arm/machine.c3
-rw-r--r--target/arm/vfp_helper.c7
3 files changed, 40 insertions, 11 deletions
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index c75b0a7..4c656bd 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -1687,15 +1687,19 @@ static inline void xpsr_write(CPUARMState *env, uint32_t val, uint32_t mask)
uint32_t vfp_get_fpscr(CPUARMState *env);
void vfp_set_fpscr(CPUARMState *env, uint32_t val);
-/* FPCR, Floating Point Control Register
- * FPSR, Floating Poiht Status Register
+/*
+ * FPCR, Floating Point Control Register
+ * FPSR, Floating Point Status Register
*
- * For A64 the FPSCR is split into two logically distinct registers,
- * FPCR and FPSR. However since they still use non-overlapping bits
- * we store the underlying state in fpscr and just mask on read/write.
+ * For A64 floating point control and status bits are stored in
+ * two logically distinct registers, FPCR and FPSR. We store these
+ * in QEMU in vfp.fpcr and vfp.fpsr.
+ * For A32 there was only one register, FPSCR. The bits are arranged
+ * such that FPSCR bits map to FPCR or FPSR bits in the same bit positions,
+ * so we can use appropriate masking to handle FPSCR reads and writes.
+ * Note that the FPCR has some bits which are not visible in the
+ * AArch32 view (for FEAT_AFP). Writing the FPSCR leaves these unchanged.
*/
-#define FPSR_MASK 0xf800009f
-#define FPCR_MASK 0x07ff9f00
/* FPCR bits */
#define FPCR_IOE (1 << 8) /* Invalid Operation exception trap enable */
@@ -1704,7 +1708,9 @@ void vfp_set_fpscr(CPUARMState *env, uint32_t val);
#define FPCR_UFE (1 << 11) /* Underflow exception trap enable */
#define FPCR_IXE (1 << 12) /* Inexact exception trap enable */
#define FPCR_IDE (1 << 15) /* Input Denormal exception trap enable */
+#define FPCR_LEN_MASK (7 << 16) /* LEN, A-profile only */
#define FPCR_FZ16 (1 << 19) /* ARMv8.2+, FP16 flush-to-zero */
+#define FPCR_STRIDE_MASK (3 << 20) /* Stride */
#define FPCR_RMODE_MASK (3 << 22) /* Rounding mode */
#define FPCR_FZ (1 << 24) /* Flush-to-zero enable bit */
#define FPCR_DN (1 << 25) /* Default NaN enable bit */
@@ -1714,16 +1720,37 @@ void vfp_set_fpscr(CPUARMState *env, uint32_t val);
#define FPCR_LTPSIZE_MASK (7 << FPCR_LTPSIZE_SHIFT)
#define FPCR_LTPSIZE_LENGTH 3
+/* Cumulative exception trap enable bits */
+#define FPCR_EEXC_MASK (FPCR_IOE | FPCR_DZE | FPCR_OFE | FPCR_UFE | FPCR_IXE | FPCR_IDE)
+
/* FPSR bits */
+#define FPSR_IOC (1 << 0) /* Invalid Operation cumulative exception */
+#define FPSR_DZC (1 << 1) /* Divide by Zero cumulative exception */
+#define FPSR_OFC (1 << 2) /* Overflow cumulative exception */
+#define FPSR_UFC (1 << 3) /* Underflow cumulative exception */
+#define FPSR_IXC (1 << 4) /* Inexact cumulative exception */
+#define FPSR_IDC (1 << 7) /* Input Denormal cumulative exception */
#define FPSR_QC (1 << 27) /* Cumulative saturation bit */
#define FPSR_V (1 << 28) /* FP overflow flag */
#define FPSR_C (1 << 29) /* FP carry flag */
#define FPSR_Z (1 << 30) /* FP zero flag */
#define FPSR_N (1 << 31) /* FP negative flag */
+/* Cumulative exception status bits */
+#define FPSR_CEXC_MASK (FPSR_IOC | FPSR_DZC | FPSR_OFC | FPSR_UFC | FPSR_IXC | FPSR_IDC)
+
#define FPSR_NZCV_MASK (FPSR_N | FPSR_Z | FPSR_C | FPSR_V)
#define FPSR_NZCVQC_MASK (FPSR_NZCV_MASK | FPSR_QC)
+/* A32 FPSCR bits which architecturally map to FPSR bits */
+#define FPSCR_FPSR_MASK (FPSR_NZCVQC_MASK | FPSR_CEXC_MASK)
+/* A32 FPSCR bits which architecturally map to FPCR bits */
+#define FPSCR_FPCR_MASK (FPCR_EEXC_MASK | FPCR_LEN_MASK | FPCR_FZ16 | \
+ FPCR_STRIDE_MASK | FPCR_RMODE_MASK | \
+ FPCR_FZ | FPCR_DN | FPCR_AHP)
+/* These masks don't overlap: each bit lives in only one place */
+QEMU_BUILD_BUG_ON(FPSCR_FPSR_MASK & FPSCR_FPCR_MASK);
+
/**
* vfp_get_fpsr: read the AArch64 FPSR
* @env: CPU context
diff --git a/target/arm/machine.c b/target/arm/machine.c
index 8c82095..a3c1e05 100644
--- a/target/arm/machine.c
+++ b/target/arm/machine.c
@@ -43,7 +43,8 @@ static bool vfp_fpcr_fpsr_needed(void *opaque)
ARMCPU *cpu = opaque;
CPUARMState *env = &cpu->env;
- return (vfp_get_fpcr(env) & ~FPCR_MASK) || (vfp_get_fpsr(env) & ~FPSR_MASK);
+ return (vfp_get_fpcr(env) & ~FPSCR_FPCR_MASK) ||
+ (vfp_get_fpsr(env) & ~FPSCR_FPSR_MASK);
}
static int get_fpscr(QEMUFile *f, void *opaque, size_t size,
diff --git a/target/arm/vfp_helper.c b/target/arm/vfp_helper.c
index 85e50ed..cbe69ae 100644
--- a/target/arm/vfp_helper.c
+++ b/target/arm/vfp_helper.c
@@ -202,7 +202,8 @@ uint32_t vfp_get_fpsr(CPUARMState *env)
uint32_t HELPER(vfp_get_fpscr)(CPUARMState *env)
{
- return (vfp_get_fpcr(env) & FPCR_MASK) | (vfp_get_fpsr(env) & FPSR_MASK);
+ return (vfp_get_fpcr(env) & FPSCR_FPCR_MASK) |
+ (vfp_get_fpsr(env) & FPSCR_FPSR_MASK);
}
uint32_t vfp_get_fpscr(CPUARMState *env)
@@ -280,8 +281,8 @@ void vfp_set_fpcr(CPUARMState *env, uint32_t val)
void HELPER(vfp_set_fpscr)(CPUARMState *env, uint32_t val)
{
- vfp_set_fpcr(env, val & FPCR_MASK);
- vfp_set_fpsr(env, val & FPSR_MASK);
+ vfp_set_fpcr(env, val & FPSCR_FPCR_MASK);
+ vfp_set_fpsr(env, val & FPSCR_FPSR_MASK);
}
void vfp_set_fpscr(CPUARMState *env, uint32_t val)