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authorAlyssa Rosenzweig <[email protected]>2020-03-01 11:22:36 -0500
committerMarge Bot <[email protected]>2020-03-03 00:03:50 +0000
commit19a449e4258174cfba13b9bab70fbab1a700fdfd (patch)
tree8f89b4e866d2b73d0e3b4d2e5dc06704582f2b5c /src/panfrost/bifrost/disassemble.c
parentdff83476c420f3f408d3d9dcf8c58e6ec89c0b1b (diff)
pan/bi: Move notes on FMA opcodes from disassembler
We're going to be shuffling around the opcode table, so let's get this moved out first. Signed-off-by: Alyssa Rosenzweig <[email protected]> Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4025>
Diffstat (limited to 'src/panfrost/bifrost/disassemble.c')
-rw-r--r--src/panfrost/bifrost/disassemble.c79
1 files changed, 0 insertions, 79 deletions
diff --git a/src/panfrost/bifrost/disassemble.c b/src/panfrost/bifrost/disassemble.c
index 5eb5ccead83..818b78880c2 100644
--- a/src/panfrost/bifrost/disassemble.c
+++ b/src/panfrost/bifrost/disassemble.c
@@ -678,29 +678,11 @@ static const struct fma_op_info FMAOpInfos[] = {
{ 0xe032c, "NOP", FMA_ONE_SRC },
{ 0xe032d, "MOV", FMA_ONE_SRC },
{ 0xe032f, "SWZ.YY.v2i16", FMA_ONE_SRC },
- // From the ARM patent US20160364209A1:
- // "Decompose v (the input) into numbers x1 and s such that v = x1 * 2^s,
- // and x1 is a floating point value in a predetermined range where the
- // value 1 is within the range and not at one extremity of the range (e.g.
- // choose a range where 1 is towards middle of range)."
- //
- // This computes x1.
{ 0xe0345, "LOG_FREXPM", FMA_ONE_SRC },
- // Given a floating point number m * 2^e, returns m * 2^{-1}. This is
- // exactly the same as the mantissa part of frexp().
{ 0xe0365, "FRCP_FREXPM", FMA_ONE_SRC },
- // Given a floating point number m * 2^e, returns m * 2^{-2} if e is even,
- // and m * 2^{-1} if e is odd. In other words, scales by powers of 4 until
- // within the range [0.25, 1). Used for square-root and reciprocal
- // square-root.
{ 0xe0375, "FSQRT_FREXPM", FMA_ONE_SRC },
- // Given a floating point number m * 2^e, computes -e - 1 as an integer.
- // Zero and infinity/NaN return 0.
{ 0xe038d, "FRCP_FREXPE", FMA_ONE_SRC },
- // Computes floor(e/2) + 1.
{ 0xe03a5, "FSQRT_FREXPE", FMA_ONE_SRC },
- // Given a floating point number m * 2^e, computes -floor(e/2) - 1 as an
- // integer.
{ 0xe03ad, "FRSQ_FREXPE", FMA_ONE_SRC },
{ 0xe03c5, "LOG_FREXPE", FMA_ONE_SRC },
{ 0xe03fa, "CLZ", FMA_ONE_SRC },
@@ -717,67 +699,6 @@ static const struct fma_op_info FMAOpInfos[] = {
{ 0xe18c5, "TRUNC", FMA_ONE_SRC },
{ 0xe19b0, "ATAN_LDEXP.Y.f32", FMA_TWO_SRC },
{ 0xe19b8, "ATAN_LDEXP.X.f32", FMA_TWO_SRC },
- // These instructions in the FMA slot, together with LSHIFT_ADD_HIGH32.i32
- // in the ADD slot, allow one to do a 64-bit addition with an extra small
- // shift on one of the sources. There are three possible scenarios:
- //
- // 1) Full 64-bit addition. Do:
- // out.x = LSHIFT_ADD_LOW32.i64 src1.x, src2.x, shift
- // out.y = LSHIFT_ADD_HIGH32.i32 src1.y, src2.y
- //
- // The shift amount is applied to src2 before adding. The shift amount, and
- // any extra bits from src2 plus the overflow bit, are sent directly from
- // FMA to ADD instead of being passed explicitly. Hence, these two must be
- // bundled together into the same instruction.
- //
- // 2) Add a 64-bit value src1 to a zero-extended 32-bit value src2. Do:
- // out.x = LSHIFT_ADD_LOW32.u32 src1.x, src2, shift
- // out.y = LSHIFT_ADD_HIGH32.i32 src1.x, 0
- //
- // Note that in this case, the second argument to LSHIFT_ADD_HIGH32 is
- // ignored, so it can actually be anything. As before, the shift is applied
- // to src2 before adding.
- //
- // 3) Add a 64-bit value to a sign-extended 32-bit value src2. Do:
- // out.x = LSHIFT_ADD_LOW32.i32 src1.x, src2, shift
- // out.y = LSHIFT_ADD_HIGH32.i32 src1.x, 0
- //
- // The only difference is the .i32 instead of .u32. Otherwise, this is
- // exactly the same as before.
- //
- // In all these instructions, the shift amount is stored where the third
- // source would be, so the shift has to be a small immediate from 0 to 7.
- // This is fine for the expected use-case of these instructions, which is
- // manipulating 64-bit pointers.
- //
- // These instructions can also be combined with various load/store
- // instructions which normally take a 64-bit pointer in order to add a
- // 32-bit or 64-bit offset to the pointer before doing the operation,
- // optionally shifting the offset. The load/store op implicity does
- // LSHIFT_ADD_HIGH32.i32 internally. Letting ptr be the pointer, and offset
- // the desired offset, the cases go as follows:
- //
- // 1) Add a 64-bit offset:
- // LSHIFT_ADD_LOW32.i64 ptr.x, offset.x, shift
- // ld_st_op ptr.y, offset.y, ...
- //
- // Note that the output of LSHIFT_ADD_LOW32.i64 is not used, instead being
- // implicitly sent to the load/store op to serve as the low 32 bits of the
- // pointer.
- //
- // 2) Add a 32-bit unsigned offset:
- // temp = LSHIFT_ADD_LOW32.u32 ptr.x, offset, shift
- // ld_st_op temp, ptr.y, ...
- //
- // Now, the low 32 bits of offset << shift + ptr are passed explicitly to
- // the ld_st_op, to match the case where there is no offset and ld_st_op is
- // called directly.
- //
- // 3) Add a 32-bit signed offset:
- // temp = LSHIFT_ADD_LOW32.i32 ptr.x, offset, shift
- // ld_st_op temp, ptr.y, ...
- //
- // Again, the same as the unsigned case except for the offset.
{ 0xe1c80, "LSHIFT_ADD_LOW32.u32", FMA_SHIFT_ADD64 },
{ 0xe1cc0, "LSHIFT_ADD_LOW32.i64", FMA_SHIFT_ADD64 },
{ 0xe1d80, "LSHIFT_ADD_LOW32.i32", FMA_SHIFT_ADD64 },