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[Qemu-devel] [PATCH 5/6] Determine the desired FPU mode
From: |
Stefan Markovic |
Subject: |
[Qemu-devel] [PATCH 5/6] Determine the desired FPU mode |
Date: |
Fri, 26 Oct 2018 16:21:06 +0200 |
From: Stefan Markovic <address@hidden>
Floating-point mode is calculated from MIPS.abiflags FP ABI value
(based on kernel implementation). Illegal combinations are rejected.
Signed-off-by: Stefan Markovic <address@hidden>
---
linux-user/mips/cpu_loop.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 75 insertions(+)
diff --git a/linux-user/mips/cpu_loop.c b/linux-user/mips/cpu_loop.c
index c9c20cf..fd96e46 100644
--- a/linux-user/mips/cpu_loop.c
+++ b/linux-user/mips/cpu_loop.c
@@ -740,6 +740,34 @@ void target_cpu_copy_regs(CPUArchState *env, struct
target_pt_regs *regs)
struct image_info *info = ts->info;
int i;
+ struct mode_req {
+ bool single;
+ bool soft;
+ bool fr1;
+ bool frdefault;
+ bool fre;
+ };
+
+ static const struct mode_req fpu_reqs[] = {
+ [MIPS_ABI_FP_ANY] = { true, true, true, true, true },
+ [MIPS_ABI_FP_DOUBLE] = { false, false, false, true, true },
+ [MIPS_ABI_FP_SINGLE] = { true, false, false, false, false },
+ [MIPS_ABI_FP_SOFT] = { false, true, false, false, false },
+ [MIPS_ABI_FP_OLD_64] = { false, false, false, false, false },
+ [MIPS_ABI_FP_XX] = { false, false, true, true, true },
+ [MIPS_ABI_FP_64] = { false, false, true, false, false },
+ [MIPS_ABI_FP_64A] = { false, false, true, false, true }
+ };
+
+ /*
+ * Mode requirements when .MIPS.abiflags is not present in the ELF.
+ * Not present means that everything is acceptable except FR1.
+ */
+ static struct mode_req none_req = { true, true, false, true, true };
+
+ struct mode_req prog_req;
+ struct mode_req interp_req;
+
for(i = 0; i < 32; i++) {
env->active_tc.gpr[i] = regs->regs[i];
}
@@ -747,6 +775,53 @@ void target_cpu_copy_regs(CPUArchState *env, struct
target_pt_regs *regs)
if (regs->cp0_epc & 1) {
env->hflags |= MIPS_HFLAG_M16;
}
+
+#ifdef TARGET_ABI_MIPSO32
+# define MAX_FP_ABI MIPS_ABI_FP_64A
+#else
+# define MAX_FP_ABI MIPS_ABI_FP_SOFT
+#endif
+ if ((info->fp_abi > MAX_FP_ABI && info->fp_abi != MIPS_ABI_FP_UNKNOWN)
+ || (info->interp_fp_abi > MAX_FP_ABI &&
+ info->interp_fp_abi != MIPS_ABI_FP_UNKNOWN)) {
+ fprintf(stderr, "qemu: Program and interpreter have "
+ "unexpected FPU modes\n");
+ exit(137);
+ }
+
+ prog_req = (info->fp_abi == MIPS_ABI_FP_UNKNOWN) ? none_req
+ : fpu_reqs[info->fp_abi];
+ interp_req = (info->interp_fp_abi == MIPS_ABI_FP_UNKNOWN) ? none_req
+ : fpu_reqs[info->interp_fp_abi];
+
+ prog_req.single &= interp_req.single;
+ prog_req.soft &= interp_req.soft;
+ prog_req.fr1 &= interp_req.fr1;
+ prog_req.frdefault &= interp_req.frdefault;
+ prog_req.fre &= interp_req.fre;
+
+ bool cpu_has_mips_r2_r6 = env->insn_flags & ISA_MIPS32R2 ||
+ env->insn_flags & ISA_MIPS64R2 ||
+ env->insn_flags & ISA_MIPS32R6 ||
+ env->insn_flags & ISA_MIPS64R6;
+
+ if (prog_req.fre && !prog_req.frdefault && !prog_req.fr1) {
+ env->CP0_Config5 |= (1 << CP0C5_FRE);
+ if (env->active_fpu.fcr0 & (1 << FCR0_FREP)) {
+ env->hflags |= MIPS_HFLAG_FRE;
+ }
+ } else if ((prog_req.fr1 && prog_req.frdefault) ||
+ (prog_req.single && !prog_req.frdefault)) {
+ if ((env->active_fpu.fcr0 & (1 << FCR0_F64)
+ && cpu_has_mips_r2_r6) || prog_req.fr1) {
+ env->CP0_Status |= (1 << CP0St_FR);
+ env->hflags |= MIPS_HFLAG_F64;
+ }
+ } else if (!prog_req.fre && !prog_req.frdefault &&
+ !prog_req.fr1 && !prog_req.single && !prog_req.soft) {
+ exit(137);
+ }
+
if (env->insn_flags & ISA_NANOMIPS32) {
return;
}
--
1.9.1
- [Qemu-devel] [PATCH 0/6] target/mips: Add support for prctl() PR_GET_FP_MODE and PR_SET_FP_MODE, Stefan Markovic, 2018/10/26
- [Qemu-devel] [PATCH 2/6] Extend image_info struct with MIPS specific fp_abi and interp_fp_abi fields, Stefan Markovic, 2018/10/26
- [Qemu-devel] [PATCH 3/6] Extract MIPS abiflags from ELF file, Stefan Markovic, 2018/10/26
- [Qemu-devel] [PATCH 4/6] Read and set FP ABI value from MIPS abiflags, Stefan Markovic, 2018/10/26
- [Qemu-devel] [PATCH 5/6] Determine the desired FPU mode,
Stefan Markovic <=
- [Qemu-devel] [PATCH 6/6] Add prctl() PR_SET_FP_MODE and PR_GET_FP_MODE implementations, Stefan Markovic, 2018/10/26
- [Qemu-devel] [PATCH 1/6] Define MIPS_ABI_FP_UNKNOWN macro, Stefan Markovic, 2018/10/26
- Re: [Qemu-devel] [PATCH 0/6] target/mips: Add support for prctl() PR_GET_FP_MODE and PR_SET_FP_MODE, Aleksandar Markovic, 2018/10/26