Permalink
Browse files

Arm64Emitter: Use Common::BitCast where applicable

Gets rid of the need to set up memcpy boilerplate to reinterpret between
floating-point and integers.

While we're at it, also do a minor bit of tidying.
  • Loading branch information...
lioncash committed May 29, 2018
1 parent 2beb135 commit 6fd7a79b93c26eff9b9fc5271481a4eb5a83de26
Showing with 22 additions and 23 deletions.
  1. +22 −23 Source/Core/Common/Arm64Emitter.cpp
@@ -11,6 +11,7 @@
#include "Common/Align.h"
#include "Common/Arm64Emitter.h"
#include "Common/Assert.h"
#include "Common/BitUtils.h"
#include "Common/CommonTypes.h"
#include "Common/MathUtil.h"
@@ -268,35 +269,34 @@ bool IsImmLogical(uint64_t value, unsigned int width, unsigned int* n, unsigned
return true;
}
float FPImm8ToFloat(uint8_t bits)
float FPImm8ToFloat(u8 bits)
{
int sign = bits >> 7;
uint32_t f = (sign << 31);
int bit6 = (bits >> 6) & 1;
uint32_t exp = ((!bit6) << 7) | (0x7C * bit6) | ((bits >> 4) & 3);
uint32_t mantissa = (bits & 0xF) << 19;
f |= exp << 23;
f |= mantissa;
float fl;
memcpy(&fl, &f, sizeof(float));
return fl;
const u32 sign = bits >> 7;
const u32 bit6 = (bits >> 6) & 1;
const u32 exp = ((!bit6) << 7) | (0x7C * bit6) | ((bits >> 4) & 3);
const u32 mantissa = (bits & 0xF) << 19;
const u32 f = (sign << 31) | (exp << 23) | mantissa;
return Common::BitCast<float>(f);
}
bool FPImm8FromFloat(float value, uint8_t* immOut)
bool FPImm8FromFloat(float value, u8* imm_out)
{
uint32_t f;
memcpy(&f, &value, sizeof(float));
uint32_t mantissa4 = (f & 0x7FFFFF) >> 19;
uint32_t exponent = (f >> 23) & 0xFF;
uint32_t sign = f >> 31;
const u32 f = Common::BitCast<u32>(value);
const u32 mantissa4 = (f & 0x7FFFFF) >> 19;
const u32 exponent = (f >> 23) & 0xFF;
const u32 sign = f >> 31;
if ((exponent >> 7) == ((exponent >> 6) & 1))
return false;
uint8_t imm8 = (sign << 7) | ((!(exponent >> 7)) << 6) | ((exponent & 3) << 4) | mantissa4;
float newFloat = FPImm8ToFloat(imm8);
if (newFloat == value)
*immOut = imm8;
const u8 imm8 = (sign << 7) | ((!(exponent >> 7)) << 6) | ((exponent & 3) << 4) | mantissa4;
const float new_float = FPImm8ToFloat(imm8);
if (new_float == value)
*imm_out = imm8;
else
return false;
return true;
}
} // Anonymous namespace
@@ -4346,11 +4346,10 @@ void ARM64FloatEmitter::MOVI2F(ARM64Reg Rd, float value, ARM64Reg scratch, bool
{
ASSERT_MSG(DYNA_REC, scratch != INVALID_REG,
"Failed to find a way to generate FP immediate %f without scratch", value);
u32 ival;
if (negate)
value = -value;
memcpy(&ival, &value, sizeof(ival));
const u32 ival = Common::BitCast<u32>(value);
m_emit->MOVI2R(scratch, ival);
FMOV(Rd, scratch);
}

0 comments on commit 6fd7a79

Please sign in to comment.