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[Qemu-ppc] [V2 PATCH 37/37] target-ppc: Introduce DFP Shift Significand
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From: |
Tom Musta |
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Subject: |
[Qemu-ppc] [V2 PATCH 37/37] target-ppc: Introduce DFP Shift Significand |
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Date: |
Mon, 21 Apr 2014 15:55:21 -0500 |
Add emulation of the PowerPC Decimal Floating Point Shift Significand
Left Immediate (dscli[q][.]) and DFP Shift Significant Right Immediate
(dscri[q][.]) instructions.
Signed-off-by: Tom Musta <address@hidden>
---
target-ppc/dfp_helper.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++
target-ppc/helper.h | 4 ++
target-ppc/translate.c | 10 +++++
3 files changed, 109 insertions(+), 0 deletions(-)
diff --git a/target-ppc/dfp_helper.c b/target-ppc/dfp_helper.c
index 130af9d..b3dca81 100644
--- a/target-ppc/dfp_helper.c
+++ b/target-ppc/dfp_helper.c
@@ -1217,3 +1217,98 @@ void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t
*a, uint64_t *b) \
DFP_HELPER_IEX(diex, 64)
DFP_HELPER_IEX(diexq, 128)
+
+static void dfp_clear_lmd_from_g5msb(uint64_t *t)
+{
+
+ /* The most significant 5 bits of the PowerPC DFP format combine bits */
+ /* from the left-most decimal digit (LMD) and the biased exponent. */
+ /* This routine clears the LMD bits while preserving the exponent */
+ /* bits. See "Figure 80: Encoding of bits 0:4 of the G field for */
+ /* Finite Numbers" in the Power ISA for additional details. */
+
+ uint64_t g5msb = (*t >> 58) & 0x1F;
+
+ if ((g5msb >> 3) < 3) { /* LMD in [0-7] ? */
+ *t &= ~(7ULL << 58);
+ } else {
+ switch (g5msb & 7) {
+ case 0:
+ case 1:
+ g5msb = 0;
+ break;
+ case 2:
+ case 3:
+ g5msb = 0x8;
+ break;
+ case 4:
+ case 5:
+ g5msb = 0x10;
+ break;
+ case 6:
+ g5msb = 0x1E;
+ break;
+ case 7:
+ g5msb = 0x1F;
+ break;
+ }
+
+ *t &= ~(0x1fULL << 58);
+ *t |= (g5msb << 58);
+ }
+}
+
+#define DFP_HELPER_SHIFT(op, size, shift_left) \
+void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *a, \
+ uint32_t sh) \
+{ \
+ struct PPC_DFP dfp; \
+ unsigned max_digits = ((size) == 64) ? 16 : 34; \
+ \
+ dfp_prepare_decimal##size(&dfp, a, 0, env); \
+ \
+ if (sh <= max_digits) { \
+ \
+ decNumber shd; \
+ unsigned special = dfp.a.bits & DECSPECIAL; \
+ \
+ if (shift_left) { \
+ decNumberFromUInt32(&shd, sh); \
+ } else { \
+ decNumberFromInt32(&shd, -((int32_t)sh)); \
+ } \
+ \
+ dfp.a.bits &= ~DECSPECIAL; \
+ decNumberShift(&dfp.t, &dfp.a, &shd, &dfp.context); \
+ \
+ dfp.t.bits |= special; \
+ if (special && (dfp.t.digits >= max_digits)) { \
+ dfp.t.digits = max_digits - 1; \
+ } \
+ \
+ decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, \
+ &dfp.context); \
+ } else { \
+ if ((size) == 64) { \
+ dfp.t64[0] = dfp.a64[0] & 0xFFFC000000000000ULL; \
+ dfp_clear_lmd_from_g5msb(dfp.t64); \
+ } else { \
+ dfp.t64[HI_IDX] = dfp.a64[HI_IDX] & \
+ 0xFFFFC00000000000ULL; \
+ dfp_clear_lmd_from_g5msb(dfp.t64 + HI_IDX); \
+ dfp.t64[LO_IDX] = 0; \
+ } \
+ } \
+ \
+ if ((size) == 64) { \
+ t[0] = dfp.t64[0]; \
+ } else { \
+ t[0] = dfp.t64[HI_IDX]; \
+ t[1] = dfp.t64[LO_IDX]; \
+ } \
+}
+
+DFP_HELPER_SHIFT(dscli, 64, 1)
+DFP_HELPER_SHIFT(dscliq, 128, 1)
+DFP_HELPER_SHIFT(dscri, 64, 0)
+DFP_HELPER_SHIFT(dscriq, 128, 0)
diff --git a/target-ppc/helper.h b/target-ppc/helper.h
index 03c86ce..0e46245 100644
--- a/target-ppc/helper.h
+++ b/target-ppc/helper.h
@@ -664,4 +664,8 @@ DEF_HELPER_3(dxex, void, env, fprp, fprp)
DEF_HELPER_3(dxexq, void, env, fprp, fprp)
DEF_HELPER_4(diex, void, env, fprp, fprp, fprp)
DEF_HELPER_4(diexq, void, env, fprp, fprp, fprp)
+DEF_HELPER_4(dscri, void, env, fprp, fprp, i32)
+DEF_HELPER_4(dscriq, void, env, fprp, fprp, i32)
+DEF_HELPER_4(dscli, void, env, fprp, fprp, i32)
+DEF_HELPER_4(dscliq, void, env, fprp, fprp, i32)
#include "exec/def-helper.h"
diff --git a/target-ppc/translate.c b/target-ppc/translate.c
index 7307345..fde6476 100644
--- a/target-ppc/translate.c
+++ b/target-ppc/translate.c
@@ -8402,6 +8402,11 @@ GEN_DFP_T_B_Rc(dxex)
GEN_DFP_T_B_Rc(dxexq)
GEN_DFP_T_A_B_Rc(diex)
GEN_DFP_T_A_B_Rc(diexq)
+GEN_DFP_T_FPR_I32_Rc(dscli, rA, DCM)
+GEN_DFP_T_FPR_I32_Rc(dscliq, rA, DCM)
+GEN_DFP_T_FPR_I32_Rc(dscri, rA, DCM)
+GEN_DFP_T_FPR_I32_Rc(dscriq, rA, DCM)
+
/*** SPE extension ***/
/* Register moves */
@@ -11375,6 +11380,11 @@ GEN_DFP_T_B_Rc(dxex, 0x02, 0x0b),
GEN_DFP_T_Bp_Rc(dxexq, 0x02, 0x0b),
GEN_DFP_T_A_B_Rc(diex, 0x02, 0x1b),
GEN_DFP_Tp_A_Bp_Rc(diexq, 0x02, 0x1b),
+GEN_DFP_T_A_SH_Rc(dscli, 0x02, 0x02),
+GEN_DFP_Tp_Ap_SH_Rc(dscliq, 0x02, 0x02),
+GEN_DFP_T_A_SH_Rc(dscri, 0x02, 0x03),
+GEN_DFP_Tp_Ap_SH_Rc(dscriq, 0x02, 0x03),
+
#undef GEN_SPE
#define GEN_SPE(name0, name1, opc2, opc3, inval0, inval1, type) \
GEN_OPCODE_DUAL(name0##_##name1, 0x04, opc2, opc3, inval0, inval1, type,
PPC_NONE)
--
1.7.1
- [Qemu-ppc] [V2 PATCH 33/37] target-ppc: Introduce DFP Decode DPD to BCD, (continued)
- [Qemu-ppc] [V2 PATCH 33/37] target-ppc: Introduce DFP Decode DPD to BCD, Tom Musta, 2014/04/21
- [Qemu-ppc] [V2 PATCH 31/37] target-ppc: Introduce DFP Convert to Fixed, Tom Musta, 2014/04/21
- [Qemu-ppc] [V2 PATCH 23/37] target-ppc: Introduce DFP Test Data Group, Tom Musta, 2014/04/21
- [Qemu-ppc] [V2 PATCH 24/37] target-ppc: Introduce DFP Test Exponent, Tom Musta, 2014/04/21
- [Qemu-ppc] [V2 PATCH 21/37] target-ppc: Introduce DFP Compares, Tom Musta, 2014/04/21
- [Qemu-ppc] [V2 PATCH 01/37] libdecnumber: Introduce libdecnumber Code, Tom Musta, 2014/04/21
- [Qemu-ppc] [V2 PATCH 35/37] target-ppc: Introduce DFP Extract Biased Exponent, Tom Musta, 2014/04/21
- [Qemu-ppc] [V2 PATCH 22/37] target-ppc: Introduce DFP Test Data Class, Tom Musta, 2014/04/21
- [Qemu-ppc] [V2 PATCH 27/37] target-ppc: Introduce DFP Reround, Tom Musta, 2014/04/21
- [Qemu-ppc] [V2 PATCH 26/37] target-ppc: Introduce DFP Quantize, Tom Musta, 2014/04/21
- [Qemu-ppc] [V2 PATCH 37/37] target-ppc: Introduce DFP Shift Significand,
Tom Musta <=
- [Qemu-ppc] [V2 PATCH 25/37] target-ppc: Introduce DFP Test Significance, Tom Musta, 2014/04/21
- [Qemu-ppc] [V2 PATCH 34/37] target-ppc: Introduce DFP Encode BCD to DPD, Tom Musta, 2014/04/21
- [Qemu-ppc] [V2 PATCH 36/37] target-ppc: Introduce DFP Insert Biased Exponent, Tom Musta, 2014/04/21