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authorGabe Black <gblack@eecs.umich.edu>2009-06-21 22:51:13 -0700
committerGabe Black <gblack@eecs.umich.edu>2009-06-21 22:51:13 -0700
commitd744525273ee4e30c68174afbe3f4c3630956ca8 (patch)
treef69789950621d89e5bf56aef8d18640a7fcbdc0a /src
parent5c2a362cb79d9aaf5fc69cf05a56d67d98f8b737 (diff)
downloadgem5-d744525273ee4e30c68174afbe3f4c3630956ca8.tar.xz
ARM: Simplify some utility functions.
Diffstat (limited to 'src')
-rw-r--r--src/arch/arm/insts/static_inst.cc256
-rw-r--r--src/arch/arm/insts/static_inst.hh42
2 files changed, 122 insertions, 176 deletions
diff --git a/src/arch/arm/insts/static_inst.cc b/src/arch/arm/insts/static_inst.cc
index 64bc9751f..aa60b57be 100644
--- a/src/arch/arm/insts/static_inst.cc
+++ b/src/arch/arm/insts/static_inst.cc
@@ -28,44 +28,42 @@
*/
#include "arch/arm/insts/static_inst.hh"
+#include "base/condcodes.hh"
namespace ArmISA
{
-static int32_t arm_NEG(int32_t val) { return (val >> 31); }
-static int32_t arm_POS(int32_t val) { return ((~val) >> 31); }
-
// Shift Rm by an immediate value
int32_t
ArmStaticInst::shift_rm_imm(uint32_t base, uint32_t shamt,
uint32_t type, uint32_t cfval) const
{
- enum ArmShiftType shiftType;
- shiftType = (enum ArmShiftType) type;
+ assert(shamt < 32);
+ ArmShiftType shiftType;
+ shiftType = (ArmShiftType)type;
switch (shiftType)
{
- case LSL:
- return (base << shamt);
- case LSR:
- if (shamt == 0)
- return (0);
- else
- return (base >> shamt);
- case ASR:
- if (shamt == 0)
- return ((uint32_t) ((int32_t) base >> 31L));
- else
- return ((uint32_t) (((int32_t) base) >> shamt));
- case ROR:
- //shamt = shamt & 0x1f;
- if (shamt == 0)
- return (cfval << 31) | (base >> 1); // RRX
- else
- return (base << (32 - shamt)) | (base >> shamt);
- default:
- fprintf(stderr, "Unhandled shift type\n");
- exit(1);
- break;
+ case LSL:
+ return base << shamt;
+ case LSR:
+ if (shamt == 0)
+ return 0;
+ else
+ return base >> shamt;
+ case ASR:
+ if (shamt == 0)
+ return (int32_t)base >> 31;
+ else
+ return (int32_t)base >> shamt;
+ case ROR:
+ if (shamt == 0)
+ return (cfval << 31) | (base >> 1); // RRX
+ else
+ return (base << (32 - shamt)) | (base >> shamt);
+ default:
+ fprintf(stderr, "Unhandled shift type\n");
+ exit(1);
+ break;
}
return 0;
}
@@ -80,44 +78,38 @@ ArmStaticInst::shift_rm_rs(uint32_t base, uint32_t shamt,
switch (shiftType)
{
- case LSL:
- if (shamt == 0)
- return (base);
- else if (shamt >= 32)
- return (0);
- else
- return (base << shamt);
- case LSR:
- if (shamt == 0)
- return (base);
- else if (shamt >= 32)
- return (0);
- else
- return (base >> shamt);
- case ASR:
- if (shamt == 0)
- return base;
- else if (shamt >= 32)
- return ((uint32_t) ((int32_t) base >> 31L));
- else
- return ((uint32_t) (((int32_t) base) >> (int) shamt));
- case ROR:
- shamt = shamt & 0x1f;
- if (shamt == 0)
- return (base);
- else
- return ((base << (32 - shamt)) | (base >> shamt));
- default:
- fprintf(stderr, "Unhandled shift type\n");
- exit(1);
- break;
+ case LSL:
+ if (shamt >= 32)
+ return 0;
+ else
+ return base << shamt;
+ case LSR:
+ if (shamt >= 32)
+ return 0;
+ else
+ return base >> shamt;
+ case ASR:
+ if (shamt >= 32)
+ return (int32_t)base >> 31;
+ else
+ return (int32_t)base >> shamt;
+ case ROR:
+ shamt = shamt & 0x1f;
+ if (shamt == 0)
+ return base;
+ else
+ return (base << (32 - shamt)) | (base >> shamt);
+ default:
+ fprintf(stderr, "Unhandled shift type\n");
+ exit(1);
+ break;
}
return 0;
}
// Generate C for a shift by immediate
-int32_t
+bool
ArmStaticInst::shift_carry_imm(uint32_t base, uint32_t shamt,
uint32_t type, uint32_t cfval) const
{
@@ -126,129 +118,101 @@ ArmStaticInst::shift_carry_imm(uint32_t base, uint32_t shamt,
switch (shiftType)
{
- case LSL:
+ case LSL:
+ if (shamt == 0)
+ return cfval;
+ else
return (base >> (32 - shamt)) & 1;
- case LSR:
- if (shamt == 0)
- return (base >> 31) & 1;
- else
- return (base >> (shamt - 1)) & 1;
- case ASR:
- if (shamt == 0)
- return (base >> 31L);
- else
- return ((uint32_t) (((int32_t) base) >> (shamt - 1))) & 1;
- case ROR:
- shamt = shamt & 0x1f;
- if (shamt == 0)
- return (base & 1); // RRX
- else
- return (base >> (shamt - 1)) & 1;
- default:
- fprintf(stderr, "Unhandled shift type\n");
- exit(1);
- break;
-
+ case LSR:
+ if (shamt == 0)
+ return (base >> 31);
+ else
+ return (base >> (shamt - 1)) & 1;
+ case ASR:
+ if (shamt == 0)
+ return (base >> 31);
+ else
+ return (base >> (shamt - 1)) & 1;
+ case ROR:
+ shamt = shamt & 0x1f;
+ if (shamt == 0)
+ return (base & 1); // RRX
+ else
+ return (base >> (shamt - 1)) & 1;
+ default:
+ fprintf(stderr, "Unhandled shift type\n");
+ exit(1);
+ break;
}
return 0;
}
// Generate C for a shift by Rs
-int32_t
+bool
ArmStaticInst::shift_carry_rs(uint32_t base, uint32_t shamt,
uint32_t type, uint32_t cfval) const
{
enum ArmShiftType shiftType;
shiftType = (enum ArmShiftType) type;
+ if (shamt == 0)
+ return cfval;
+
switch (shiftType)
{
- case LSL:
- if (shamt == 0)
- return (!!cfval);
- else if (shamt == 32)
- return (base & 1);
- else if (shamt > 32)
- return (0);
- else
- return ((base >> (32 - shamt)) & 1);
- case LSR:
- if (shamt == 0)
- return (!!cfval);
- else if (shamt == 32)
- return (base >> 31);
- else if (shamt > 32)
- return (0);
- else
- return ((base >> (shamt - 1)) & 1);
- case ASR:
- if (shamt == 0)
- return (!!cfval);
- else if (shamt >= 32)
- return (base >> 31L);
- else
- return (((uint32_t) (((int32_t) base) >> (shamt - 1))) & 1);
- case ROR:
- if (shamt == 0)
- return (!!cfval);
- shamt = shamt & 0x1f;
- if (shamt == 0)
- return (base >> 31); // RRX
- else
- return ((base >> (shamt - 1)) & 1);
- default:
- fprintf(stderr, "Unhandled shift type\n");
- exit(1);
- break;
-
+ case LSL:
+ if (shamt > 32)
+ return 0;
+ else
+ return (base >> (32 - shamt)) & 1;
+ case LSR:
+ if (shamt > 32)
+ return 0;
+ else
+ return (base >> (shamt - 1)) & 1;
+ case ASR:
+ if (shamt > 32)
+ shamt = 32;
+ return (base >> (shamt - 1)) & 1;
+ case ROR:
+ shamt = shamt & 0x1f;
+ if (shamt == 0)
+ shamt = 32;
+ return (base >> (shamt - 1)) & 1;
+ default:
+ fprintf(stderr, "Unhandled shift type\n");
+ exit(1);
+ break;
}
return 0;
}
// Generate the appropriate carry bit for an addition operation
-int32_t
+bool
ArmStaticInst::arm_add_carry(int32_t result, int32_t lhs, int32_t rhs) const
{
- if ((lhs | rhs) >> 30)
- return ((arm_NEG(lhs) && arm_NEG(rhs)) ||
- (arm_NEG(lhs) && arm_POS(result)) ||
- (arm_NEG(rhs) && arm_POS(result)));
-
- return 0;
+ return findCarry(32, result, lhs, rhs);
}
// Generate the appropriate carry bit for a subtraction operation
-int32_t
+bool
ArmStaticInst::arm_sub_carry(int32_t result, int32_t lhs, int32_t rhs) const
{
- if ((lhs >= rhs) || ((rhs | lhs) >> 31))
- return ((arm_NEG(lhs) && arm_POS(rhs)) ||
- (arm_NEG(lhs) && arm_POS(result)) ||
- (arm_POS(rhs) && arm_POS(result)));
-
- return 0;
+ return findCarry(32, result, lhs, ~rhs);
}
-int32_t
+bool
ArmStaticInst::arm_add_overflow(int32_t result, int32_t lhs, int32_t rhs) const
{
- if ((lhs | rhs) >> 30)
- return ((arm_NEG(lhs) && arm_NEG(rhs) && arm_POS(result)) ||
- (arm_POS(lhs) && arm_POS(rhs) && arm_NEG(result)));
-
- return 0;
+ return findOverflow(32, result, lhs, rhs);
}
-int32_t
+bool
ArmStaticInst::arm_sub_overflow(int32_t result, int32_t lhs, int32_t rhs) const
{
- if ((lhs >= rhs) || ((rhs | lhs) >> 31))
- return ((arm_NEG(lhs) && arm_POS(rhs) && arm_POS(result)) ||
- (arm_POS(lhs) && arm_NEG(rhs) && arm_NEG(result)));
-
- return 0;
+ return findOverflow(32, result, lhs, ~rhs);
}
void
diff --git a/src/arch/arm/insts/static_inst.hh b/src/arch/arm/insts/static_inst.hh
index 9ee166ecb..6321f0de9 100644
--- a/src/arch/arm/insts/static_inst.hh
+++ b/src/arch/arm/insts/static_inst.hh
@@ -37,39 +37,21 @@ namespace ArmISA
class ArmStaticInst : public StaticInst
{
protected:
- // Shift Rm by an immediate value
- int32_t
- shift_rm_imm(uint32_t base, uint32_t shamt,
- uint32_t type, uint32_t cfval) const;
+ int32_t shift_rm_imm(uint32_t base, uint32_t shamt,
+ uint32_t type, uint32_t cfval) const;
+ int32_t shift_rm_rs(uint32_t base, uint32_t shamt,
+ uint32_t type, uint32_t cfval) const;
- // Shift Rm by Rs
- int32_t
- shift_rm_rs(uint32_t base, uint32_t shamt,
- uint32_t type, uint32_t cfval) const;
+ bool shift_carry_imm(uint32_t base, uint32_t shamt,
+ uint32_t type, uint32_t cfval) const;
+ bool shift_carry_rs(uint32_t base, uint32_t shamt,
+ uint32_t type, uint32_t cfval) const;
- // Generate C for a shift by immediate
- int32_t
- shift_carry_imm(uint32_t base, uint32_t shamt,
- uint32_t type, uint32_t cfval) const;
+ bool arm_add_carry(int32_t result, int32_t lhs, int32_t rhs) const;
+ bool arm_sub_carry(int32_t result, int32_t lhs, int32_t rhs) const;
- // Generate C for a shift by Rs
- int32_t
- shift_carry_rs(uint32_t base, uint32_t shamt,
- uint32_t type, uint32_t cfval) const;
-
- // Generate the appropriate carry bit for an addition operation
- int32_t
- arm_add_carry(int32_t result, int32_t lhs, int32_t rhs) const;
-
- // Generate the appropriate carry bit for a subtraction operation
- int32_t
- arm_sub_carry(int32_t result, int32_t lhs, int32_t rhs) const;
-
- int32_t
- arm_add_overflow(int32_t result, int32_t lhs, int32_t rhs) const;
-
- int32_t
- arm_sub_overflow(int32_t result, int32_t lhs, int32_t rhs) const;
+ bool arm_add_overflow(int32_t result, int32_t lhs, int32_t rhs) const;
+ bool arm_sub_overflow(int32_t result, int32_t lhs, int32_t rhs) const;
// Constructor
ArmStaticInst(const char *mnem, MachInst _machInst, OpClass __opClass)