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[PULL 24/42] target/ppc: overhauled and moved logic of storing fpscr
From: |
David Gibson |
Subject: |
[PULL 24/42] target/ppc: overhauled and moved logic of storing fpscr |
Date: |
Thu, 3 Jun 2021 18:22:13 +1000 |
From: "Bruno Larsen (billionai)" <bruno.larsen@eldorado.org.br>
Followed the suggested overhaul to store_fpscr logic, and moved it to
cpu.c where it can be accessed in !TCG builds.
The overhaul was suggested because storing a value to fpscr should
never raise an exception, so we could remove all the mess that happened
with POWERPC_EXCP_FP.
We also moved fpscr_set_rounding_mode into cpu.c as it could now be moved
there, and it is needed when a value for the fpscr is being stored
directly.
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Bruno Larsen (billionai) <bruno.larsen@eldorado.org.br>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210527163522.23019-1-bruno.larsen@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
target/ppc/cpu.c | 43 ++++++++
target/ppc/cpu.h | 12 +-
target/ppc/fpu_helper.c | 238 +++-------------------------------------
target/ppc/gdbstub.c | 6 +-
4 files changed, 65 insertions(+), 234 deletions(-)
diff --git a/target/ppc/cpu.c b/target/ppc/cpu.c
index c8e87e30f1..19d67b5b07 100644
--- a/target/ppc/cpu.c
+++ b/target/ppc/cpu.c
@@ -25,6 +25,7 @@
#include "fpu/softfloat-helpers.h"
#include "mmu-hash64.h"
#include "helper_regs.h"
+#include "sysemu/tcg.h"
target_ulong cpu_read_xer(CPUPPCState *env)
{
@@ -109,3 +110,45 @@ void ppc_store_lpcr(PowerPCCPU *cpu, target_ulong val)
/* The gtse bit affects hflags */
hreg_compute_hflags(env);
}
+
+static inline void fpscr_set_rounding_mode(CPUPPCState *env)
+{
+ int rnd_type;
+
+ /* Set rounding mode */
+ switch (fpscr_rn) {
+ case 0:
+ /* Best approximation (round to nearest) */
+ rnd_type = float_round_nearest_even;
+ break;
+ case 1:
+ /* Smaller magnitude (round toward zero) */
+ rnd_type = float_round_to_zero;
+ break;
+ case 2:
+ /* Round toward +infinite */
+ rnd_type = float_round_up;
+ break;
+ default:
+ case 3:
+ /* Round toward -infinite */
+ rnd_type = float_round_down;
+ break;
+ }
+ set_float_rounding_mode(rnd_type, &env->fp_status);
+}
+
+void ppc_store_fpscr(CPUPPCState *env, target_ulong val)
+{
+ val &= ~(FP_VX | FP_FEX);
+ if (val & FPSCR_IX) {
+ val |= FP_VX;
+ }
+ if ((val >> FPSCR_XX) & (val >> FPSCR_XE) & 0x1f) {
+ val |= FP_FEX;
+ }
+ env->fpscr = val;
+ if (tcg_enabled()) {
+ fpscr_set_rounding_mode(env);
+ }
+}
diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
index b0934d9be4..b7ae4902e4 100644
--- a/target/ppc/cpu.h
+++ b/target/ppc/cpu.h
@@ -675,11 +675,11 @@ enum {
#define fpscr_ni (((env->fpscr) >> FPSCR_NI) & 0x1)
#define fpscr_rn (((env->fpscr) >> FPSCR_RN0) & 0x3)
/* Invalid operation exception summary */
-#define fpscr_ix ((env->fpscr) & ((1 << FPSCR_VXSNAN) | (1 << FPSCR_VXISI) | \
- (1 << FPSCR_VXIDI) | (1 << FPSCR_VXZDZ) | \
- (1 << FPSCR_VXIMZ) | (1 << FPSCR_VXVC) | \
- (1 << FPSCR_VXSOFT) | (1 << FPSCR_VXSQRT) | \
- (1 << FPSCR_VXCVI)))
+#define FPSCR_IX ((1 << FPSCR_VXSNAN) | (1 << FPSCR_VXISI) | \
+ (1 << FPSCR_VXIDI) | (1 << FPSCR_VXZDZ) | \
+ (1 << FPSCR_VXIMZ) | (1 << FPSCR_VXVC) | \
+ (1 << FPSCR_VXSOFT) | (1 << FPSCR_VXSQRT) | \
+ (1 << FPSCR_VXCVI))
/* exception summary */
#define fpscr_ex (((env->fpscr) >> FPSCR_XX) & 0x1F)
/* enabled exception summary */
@@ -1332,7 +1332,7 @@ void cpu_ppc_set_vhyp(PowerPCCPU *cpu,
PPCVirtualHypervisor *vhyp);
#endif
#endif
-void store_fpscr(CPUPPCState *env, uint64_t arg, uint32_t mask);
+void ppc_store_fpscr(CPUPPCState *env, target_ulong val);
void helper_hfscr_facility_check(CPUPPCState *env, uint32_t bit,
const char *caller, uint32_t cause);
diff --git a/target/ppc/fpu_helper.c b/target/ppc/fpu_helper.c
index a4a283df2b..c4896cecc8 100644
--- a/target/ppc/fpu_helper.c
+++ b/target/ppc/fpu_helper.c
@@ -383,247 +383,35 @@ static inline void float_inexact_excp(CPUPPCState *env)
}
}
-static inline void fpscr_set_rounding_mode(CPUPPCState *env)
-{
- int rnd_type;
-
- /* Set rounding mode */
- switch (fpscr_rn) {
- case 0:
- /* Best approximation (round to nearest) */
- rnd_type = float_round_nearest_even;
- break;
- case 1:
- /* Smaller magnitude (round toward zero) */
- rnd_type = float_round_to_zero;
- break;
- case 2:
- /* Round toward +infinite */
- rnd_type = float_round_up;
- break;
- default:
- case 3:
- /* Round toward -infinite */
- rnd_type = float_round_down;
- break;
- }
- set_float_rounding_mode(rnd_type, &env->fp_status);
-}
-
void helper_fpscr_clrbit(CPUPPCState *env, uint32_t bit)
{
- int prev;
-
- prev = (env->fpscr >> bit) & 1;
- env->fpscr &= ~(1 << bit);
- if (prev == 1) {
- switch (bit) {
- case FPSCR_RN1:
- case FPSCR_RN0:
- fpscr_set_rounding_mode(env);
- break;
- case FPSCR_VXSNAN:
- case FPSCR_VXISI:
- case FPSCR_VXIDI:
- case FPSCR_VXZDZ:
- case FPSCR_VXIMZ:
- case FPSCR_VXVC:
- case FPSCR_VXSOFT:
- case FPSCR_VXSQRT:
- case FPSCR_VXCVI:
- if (!fpscr_ix) {
- /* Set VX bit to zero */
- env->fpscr &= ~FP_VX;
- }
- break;
- case FPSCR_OX:
- case FPSCR_UX:
- case FPSCR_ZX:
- case FPSCR_XX:
- case FPSCR_VE:
- case FPSCR_OE:
- case FPSCR_UE:
- case FPSCR_ZE:
- case FPSCR_XE:
- if (!fpscr_eex) {
- /* Set the FEX bit */
- env->fpscr &= ~FP_FEX;
- }
- break;
- default:
- break;
- }
+ uint32_t mask = 1u << bit;
+ if (env->fpscr & mask) {
+ ppc_store_fpscr(env, env->fpscr & ~(target_ulong)mask);
}
}
void helper_fpscr_setbit(CPUPPCState *env, uint32_t bit)
{
- CPUState *cs = env_cpu(env);
- int prev;
-
- prev = (env->fpscr >> bit) & 1;
- env->fpscr |= 1 << bit;
- if (prev == 0) {
- switch (bit) {
- case FPSCR_VX:
- env->fpscr |= FP_FX;
- if (fpscr_ve) {
- goto raise_ve;
- }
- break;
- case FPSCR_OX:
- env->fpscr |= FP_FX;
- if (fpscr_oe) {
- goto raise_oe;
- }
- break;
- case FPSCR_UX:
- env->fpscr |= FP_FX;
- if (fpscr_ue) {
- goto raise_ue;
- }
- break;
- case FPSCR_ZX:
- env->fpscr |= FP_FX;
- if (fpscr_ze) {
- goto raise_ze;
- }
- break;
- case FPSCR_XX:
- env->fpscr |= FP_FX;
- if (fpscr_xe) {
- goto raise_xe;
- }
- break;
- case FPSCR_VXSNAN:
- case FPSCR_VXISI:
- case FPSCR_VXIDI:
- case FPSCR_VXZDZ:
- case FPSCR_VXIMZ:
- case FPSCR_VXVC:
- case FPSCR_VXSOFT:
- case FPSCR_VXSQRT:
- case FPSCR_VXCVI:
- env->fpscr |= FP_VX;
- env->fpscr |= FP_FX;
- if (fpscr_ve != 0) {
- goto raise_ve;
- }
- break;
- case FPSCR_VE:
- if (fpscr_vx != 0) {
- raise_ve:
- env->error_code = POWERPC_EXCP_FP;
- if (fpscr_vxsnan) {
- env->error_code |= POWERPC_EXCP_FP_VXSNAN;
- }
- if (fpscr_vxisi) {
- env->error_code |= POWERPC_EXCP_FP_VXISI;
- }
- if (fpscr_vxidi) {
- env->error_code |= POWERPC_EXCP_FP_VXIDI;
- }
- if (fpscr_vxzdz) {
- env->error_code |= POWERPC_EXCP_FP_VXZDZ;
- }
- if (fpscr_vximz) {
- env->error_code |= POWERPC_EXCP_FP_VXIMZ;
- }
- if (fpscr_vxvc) {
- env->error_code |= POWERPC_EXCP_FP_VXVC;
- }
- if (fpscr_vxsoft) {
- env->error_code |= POWERPC_EXCP_FP_VXSOFT;
- }
- if (fpscr_vxsqrt) {
- env->error_code |= POWERPC_EXCP_FP_VXSQRT;
- }
- if (fpscr_vxcvi) {
- env->error_code |= POWERPC_EXCP_FP_VXCVI;
- }
- goto raise_excp;
- }
- break;
- case FPSCR_OE:
- if (fpscr_ox != 0) {
- raise_oe:
- env->error_code = POWERPC_EXCP_FP | POWERPC_EXCP_FP_OX;
- goto raise_excp;
- }
- break;
- case FPSCR_UE:
- if (fpscr_ux != 0) {
- raise_ue:
- env->error_code = POWERPC_EXCP_FP | POWERPC_EXCP_FP_UX;
- goto raise_excp;
- }
- break;
- case FPSCR_ZE:
- if (fpscr_zx != 0) {
- raise_ze:
- env->error_code = POWERPC_EXCP_FP | POWERPC_EXCP_FP_ZX;
- goto raise_excp;
- }
- break;
- case FPSCR_XE:
- if (fpscr_xx != 0) {
- raise_xe:
- env->error_code = POWERPC_EXCP_FP | POWERPC_EXCP_FP_XX;
- goto raise_excp;
- }
- break;
- case FPSCR_RN1:
- case FPSCR_RN0:
- fpscr_set_rounding_mode(env);
- break;
- default:
- break;
- raise_excp:
- /* Update the floating-point enabled exception summary */
- env->fpscr |= FP_FEX;
- /* We have to update Rc1 before raising the exception */
- cs->exception_index = POWERPC_EXCP_PROGRAM;
- break;
- }
+ uint32_t mask = 1u << bit;
+ if (!(env->fpscr & mask)) {
+ ppc_store_fpscr(env, env->fpscr | mask);
}
}
-void helper_store_fpscr(CPUPPCState *env, uint64_t arg, uint32_t mask)
+void helper_store_fpscr(CPUPPCState *env, uint64_t val, uint32_t nibbles)
{
- CPUState *cs = env_cpu(env);
- target_ulong prev, new;
+ target_ulong mask = 0;
int i;
- prev = env->fpscr;
- new = (target_ulong)arg;
- new &= ~(FP_FEX | FP_VX);
- new |= prev & (FP_FEX | FP_VX);
+ /* TODO: push this extension back to translation time */
for (i = 0; i < sizeof(target_ulong) * 2; i++) {
- if (mask & (1 << i)) {
- env->fpscr &= ~(0xFLL << (4 * i));
- env->fpscr |= new & (0xFLL << (4 * i));
+ if (nibbles & (1 << i)) {
+ mask |= (target_ulong) 0xf << (4 * i);
}
}
- /* Update VX and FEX */
- if (fpscr_ix != 0) {
- env->fpscr |= FP_VX;
- } else {
- env->fpscr &= ~FP_VX;
- }
- if ((fpscr_ex & fpscr_eex) != 0) {
- env->fpscr |= FP_FEX;
- cs->exception_index = POWERPC_EXCP_PROGRAM;
- /* XXX: we should compute it properly */
- env->error_code = POWERPC_EXCP_FP;
- } else {
- env->fpscr &= ~FP_FEX;
- }
- fpscr_set_rounding_mode(env);
-}
-
-void store_fpscr(CPUPPCState *env, uint64_t arg, uint32_t mask)
-{
- helper_store_fpscr(env, arg, mask);
+ val = (val & mask) | (env->fpscr & ~mask);
+ ppc_store_fpscr(env, val);
}
static void do_float_check_status(CPUPPCState *env, uintptr_t raddr)
diff --git a/target/ppc/gdbstub.c b/target/ppc/gdbstub.c
index 308b98fc90..09ff1328d4 100644
--- a/target/ppc/gdbstub.c
+++ b/target/ppc/gdbstub.c
@@ -271,7 +271,7 @@ int ppc_cpu_gdb_write_register(CPUState *cs, uint8_t
*mem_buf, int n)
break;
case 70:
/* fpscr */
- store_fpscr(env, ldtul_p(mem_buf), 0xffffffff);
+ ppc_store_fpscr(env, ldtul_p(mem_buf));
break;
}
}
@@ -321,7 +321,7 @@ int ppc_cpu_gdb_write_register_apple(CPUState *cs, uint8_t
*mem_buf, int n)
break;
case 70 + 32:
/* fpscr */
- store_fpscr(env, ldq_p(mem_buf), 0xffffffff);
+ ppc_store_fpscr(env, ldq_p(mem_buf));
break;
}
}
@@ -474,7 +474,7 @@ static int gdb_set_float_reg(CPUPPCState *env, uint8_t
*mem_buf, int n)
}
if (n == 32) {
ppc_maybe_bswap_register(env, mem_buf, 4);
- store_fpscr(env, ldl_p(mem_buf), 0xffffffff);
+ ppc_store_fpscr(env, ldl_p(mem_buf));
return 4;
}
return 0;
--
2.31.1
- [PULL 05/42] spapr: Don't hijack current_machine->boot_order, (continued)
- [PULL 05/42] spapr: Don't hijack current_machine->boot_order, David Gibson, 2021/06/03
- [PULL 12/42] target/ppc: used ternary operator when registering MAS, David Gibson, 2021/06/03
- [PULL 14/42] target/ppc: created tcg-stub.c file, David Gibson, 2021/06/03
- [PULL 08/42] spapr: nvdimm: Fix the persistent-memory root node name in device tree, David Gibson, 2021/06/03
- [PULL 09/42] target/ppc: fold ppc_store_ptcr into it's only caller, David Gibson, 2021/06/03
- [PULL 13/42] target/ppc: added ifdefs around TCG-only code, David Gibson, 2021/06/03
- [PULL 18/42] monitor: removed cpustats command, David Gibson, 2021/06/03
- [PULL 21/42] HMP: added info cpustats to removed_features.rst, David Gibson, 2021/06/03
- [PULL 17/42] target/ppc: removed mentions to DO_PPC_STATISTICS, David Gibson, 2021/06/03
- [PULL 20/42] hw/core/cpu: removed cpu_dump_statistics function, David Gibson, 2021/06/03
- [PULL 24/42] target/ppc: overhauled and moved logic of storing fpscr,
David Gibson <=
- [PULL 23/42] target/ppc: removed all mentions to PPC_DUMP_CPU, David Gibson, 2021/06/03
- [PULL 22/42] target/ppc: removed GEN_OPCODE decision tree, David Gibson, 2021/06/03
- [PULL 15/42] target/ppc: updated meson.build to support disable-tcg, David Gibson, 2021/06/03
- [PULL 16/42] target/ppc: remove ppc_cpu_dump_statistics, David Gibson, 2021/06/03
- [PULL 31/42] target/ppc: Move ADDI, ADDIS to decodetree, implement PADDI, David Gibson, 2021/06/03
- [PULL 19/42] ppc/pef.c: initialize cgs->ready in kvmppc_svm_init(), David Gibson, 2021/06/03
- [PULL 25/42] target/ppc: powerpc_excp: Move lpes code to where it is used, David Gibson, 2021/06/03
- [PULL 32/42] target/ppc: Implement PNOP, David Gibson, 2021/06/03
- [PULL 36/42] target/ppc: Implement prefixed integer store instructions, David Gibson, 2021/06/03
- [PULL 28/42] target/ppc: Introduce macros to check isa extensions, David Gibson, 2021/06/03