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authorRichard Henderson <richard.henderson@linaro.org>2019-02-21 18:17:45 +0000
committerPeter Maydell <peter.maydell@linaro.org>2019-02-21 18:17:45 +0000
commite80941bd64cc388554770fd72334e9e7d459a1ef (patch)
tree8066ea1f84542a381375267d95c736296162c432
parent37356079fcdb34e13abbed8ea0c00ca880c31247 (diff)
downloadqemu-arm-e80941bd64cc388554770fd72334e9e7d459a1ef.tar.gz
target/arm: Rearrange Floating-point data-processing (2 regs)
There are lots of special cases within these insns. Split the major argument decode/loading/saving into no_output (compares), rd_is_dp, and rm_is_dp. We still need to special case argument load for compare (rd as input, rm as zero) and vcvt fixed (rd as input+output), but lots of special cases do disappear. Now that we have a full switch at the beginning, hoist the ISA checks from the code generation. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20190215192302.27855-4-richard.henderson@linaro.org Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
-rw-r--r--target/arm/translate.c227
1 files changed, 111 insertions, 116 deletions
diff --git a/target/arm/translate.c b/target/arm/translate.c
index dac737f6ca..64c5fe0df3 100644
--- a/target/arm/translate.c
+++ b/target/arm/translate.c
@@ -3639,52 +3639,108 @@ static int disas_vfp_insn(DisasContext *s, uint32_t insn)
}
} else {
/* data processing */
+ bool rd_is_dp = dp;
+ bool rm_is_dp = dp;
+ bool no_output = false;
+
/* The opcode is in bits 23, 21, 20 and 6. */
op = ((insn >> 20) & 8) | ((insn >> 19) & 6) | ((insn >> 6) & 1);
- if (dp) {
- if (op == 15) {
- /* rn is opcode */
- rn = ((insn >> 15) & 0x1e) | ((insn >> 7) & 1);
- } else {
- /* rn is register number */
- VFP_DREG_N(rn, insn);
- }
+ rn = VFP_SREG_N(insn);
- if (op == 15 && (rn == 15 || ((rn & 0x1c) == 0x18) ||
- ((rn & 0x1e) == 0x6))) {
- /* Integer or single/half precision destination. */
- rd = VFP_SREG_D(insn);
- } else {
- VFP_DREG_D(rd, insn);
- }
- if (op == 15 &&
- (((rn & 0x1c) == 0x10) || ((rn & 0x14) == 0x14) ||
- ((rn & 0x1e) == 0x4))) {
- /* VCVT from int or half precision is always from S reg
- * regardless of dp bit. VCVT with immediate frac_bits
- * has same format as SREG_M.
+ if (op == 15) {
+ /* rn is opcode, encoded as per VFP_SREG_N. */
+ switch (rn) {
+ case 0x00: /* vmov */
+ case 0x01: /* vabs */
+ case 0x02: /* vneg */
+ case 0x03: /* vsqrt */
+ break;
+
+ case 0x04: /* vcvtb.f64.f16, vcvtb.f32.f16 */
+ case 0x05: /* vcvtt.f64.f16, vcvtt.f32.f16 */
+ /*
+ * VCVTB, VCVTT: only present with the halfprec extension
+ * UNPREDICTABLE if bit 8 is set prior to ARMv8
+ * (we choose to UNDEF)
*/
- rm = VFP_SREG_M(insn);
- } else {
- VFP_DREG_M(rm, insn);
+ if ((dp && !arm_dc_feature(s, ARM_FEATURE_V8)) ||
+ !arm_dc_feature(s, ARM_FEATURE_VFP_FP16)) {
+ return 1;
+ }
+ rm_is_dp = false;
+ break;
+ case 0x06: /* vcvtb.f16.f32, vcvtb.f16.f64 */
+ case 0x07: /* vcvtt.f16.f32, vcvtt.f16.f64 */
+ if ((dp && !arm_dc_feature(s, ARM_FEATURE_V8)) ||
+ !arm_dc_feature(s, ARM_FEATURE_VFP_FP16)) {
+ return 1;
+ }
+ rd_is_dp = false;
+ break;
+
+ case 0x08: case 0x0a: /* vcmp, vcmpz */
+ case 0x09: case 0x0b: /* vcmpe, vcmpez */
+ no_output = true;
+ break;
+
+ case 0x0c: /* vrintr */
+ case 0x0d: /* vrintz */
+ case 0x0e: /* vrintx */
+ break;
+
+ case 0x0f: /* vcvt double<->single */
+ rd_is_dp = !dp;
+ break;
+
+ case 0x10: /* vcvt.fxx.u32 */
+ case 0x11: /* vcvt.fxx.s32 */
+ rm_is_dp = false;
+ break;
+ case 0x18: /* vcvtr.u32.fxx */
+ case 0x19: /* vcvtz.u32.fxx */
+ case 0x1a: /* vcvtr.s32.fxx */
+ case 0x1b: /* vcvtz.s32.fxx */
+ rd_is_dp = false;
+ break;
+
+ case 0x14: /* vcvt fp <-> fixed */
+ case 0x15:
+ case 0x16:
+ case 0x17:
+ case 0x1c:
+ case 0x1d:
+ case 0x1e:
+ case 0x1f:
+ if (!arm_dc_feature(s, ARM_FEATURE_VFP3)) {
+ return 1;
+ }
+ /* Immediate frac_bits has same format as SREG_M. */
+ rm_is_dp = false;
+ break;
+
+ default:
+ return 1;
}
+ } else if (dp) {
+ /* rn is register number */
+ VFP_DREG_N(rn, insn);
+ }
+
+ if (rd_is_dp) {
+ VFP_DREG_D(rd, insn);
+ } else {
+ rd = VFP_SREG_D(insn);
+ }
+ if (rm_is_dp) {
+ VFP_DREG_M(rm, insn);
} else {
- rn = VFP_SREG_N(insn);
- if (op == 15 && rn == 15) {
- /* Double precision destination. */
- VFP_DREG_D(rd, insn);
- } else {
- rd = VFP_SREG_D(insn);
- }
- /* NB that we implicitly rely on the encoding for the frac_bits
- * in VCVT of fixed to float being the same as that of an SREG_M
- */
rm = VFP_SREG_M(insn);
}
veclen = s->vec_len;
- if (op == 15 && rn > 3)
+ if (op == 15 && rn > 3) {
veclen = 0;
+ }
/* Shut up compiler warnings. */
delta_m = 0;
@@ -3720,55 +3776,28 @@ static int disas_vfp_insn(DisasContext *s, uint32_t insn)
/* Load the initial operands. */
if (op == 15) {
switch (rn) {
- case 16:
- case 17:
- /* Integer source */
- gen_mov_F0_vreg(0, rm);
- break;
- case 8:
- case 9:
- /* Compare */
+ case 0x08: case 0x09: /* Compare */
gen_mov_F0_vreg(dp, rd);
gen_mov_F1_vreg(dp, rm);
break;
- case 10:
- case 11:
- /* Compare with zero */
+ case 0x0a: case 0x0b: /* Compare with zero */
gen_mov_F0_vreg(dp, rd);
gen_vfp_F1_ld0(dp);
break;
- case 20:
- case 21:
- case 22:
- case 23:
- case 28:
- case 29:
- case 30:
- case 31:
+ case 0x14: /* vcvt fp <-> fixed */
+ case 0x15:
+ case 0x16:
+ case 0x17:
+ case 0x1c:
+ case 0x1d:
+ case 0x1e:
+ case 0x1f:
/* Source and destination the same. */
gen_mov_F0_vreg(dp, rd);
break;
- case 4:
- case 5:
- case 6:
- case 7:
- /* VCVTB, VCVTT: only present with the halfprec extension
- * UNPREDICTABLE if bit 8 is set prior to ARMv8
- * (we choose to UNDEF)
- */
- if ((dp && !arm_dc_feature(s, ARM_FEATURE_V8)) ||
- !arm_dc_feature(s, ARM_FEATURE_VFP_FP16)) {
- return 1;
- }
- if (!extract32(rn, 1, 1)) {
- /* Half precision source. */
- gen_mov_F0_vreg(0, rm);
- break;
- }
- /* Otherwise fall through */
default:
/* One source operand. */
- gen_mov_F0_vreg(dp, rm);
+ gen_mov_F0_vreg(rm_is_dp, rm);
break;
}
} else {
@@ -4047,10 +4076,11 @@ static int disas_vfp_insn(DisasContext *s, uint32_t insn)
break;
}
case 15: /* single<->double conversion */
- if (dp)
+ if (dp) {
gen_helper_vfp_fcvtsd(cpu_F0s, cpu_F0d, cpu_env);
- else
+ } else {
gen_helper_vfp_fcvtds(cpu_F0d, cpu_F0s, cpu_env);
+ }
break;
case 16: /* fuito */
gen_vfp_uito(dp, 0);
@@ -4059,27 +4089,15 @@ static int disas_vfp_insn(DisasContext *s, uint32_t insn)
gen_vfp_sito(dp, 0);
break;
case 20: /* fshto */
- if (!arm_dc_feature(s, ARM_FEATURE_VFP3)) {
- return 1;
- }
gen_vfp_shto(dp, 16 - rm, 0);
break;
case 21: /* fslto */
- if (!arm_dc_feature(s, ARM_FEATURE_VFP3)) {
- return 1;
- }
gen_vfp_slto(dp, 32 - rm, 0);
break;
case 22: /* fuhto */
- if (!arm_dc_feature(s, ARM_FEATURE_VFP3)) {
- return 1;
- }
gen_vfp_uhto(dp, 16 - rm, 0);
break;
case 23: /* fulto */
- if (!arm_dc_feature(s, ARM_FEATURE_VFP3)) {
- return 1;
- }
gen_vfp_ulto(dp, 32 - rm, 0);
break;
case 24: /* ftoui */
@@ -4095,57 +4113,34 @@ static int disas_vfp_insn(DisasContext *s, uint32_t insn)
gen_vfp_tosiz(dp, 0);
break;
case 28: /* ftosh */
- if (!arm_dc_feature(s, ARM_FEATURE_VFP3)) {
- return 1;
- }
gen_vfp_tosh(dp, 16 - rm, 0);
break;
case 29: /* ftosl */
- if (!arm_dc_feature(s, ARM_FEATURE_VFP3)) {
- return 1;
- }
gen_vfp_tosl(dp, 32 - rm, 0);
break;
case 30: /* ftouh */
- if (!arm_dc_feature(s, ARM_FEATURE_VFP3)) {
- return 1;
- }
gen_vfp_touh(dp, 16 - rm, 0);
break;
case 31: /* ftoul */
- if (!arm_dc_feature(s, ARM_FEATURE_VFP3)) {
- return 1;
- }
gen_vfp_toul(dp, 32 - rm, 0);
break;
default: /* undefined */
- return 1;
+ g_assert_not_reached();
}
break;
default: /* undefined */
return 1;
}
- /* Write back the result. */
- if (op == 15 && (rn >= 8 && rn <= 11)) {
- /* Comparison, do nothing. */
- } else if (op == 15 && dp && ((rn & 0x1c) == 0x18 ||
- (rn & 0x1e) == 0x6)) {
- /* VCVT double to int: always integer result.
- * VCVT double to half precision is always a single
- * precision result.
- */
- gen_mov_vreg_F0(0, rd);
- } else if (op == 15 && rn == 15) {
- /* conversion */
- gen_mov_vreg_F0(!dp, rd);
- } else {
- gen_mov_vreg_F0(dp, rd);
+ /* Write back the result, if any. */
+ if (!no_output) {
+ gen_mov_vreg_F0(rd_is_dp, rd);
}
/* break out of the loop if we have finished */
- if (veclen == 0)
+ if (veclen == 0) {
break;
+ }
if (op == 15 && delta_m == 0) {
/* single source one-many */