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arch-vega: Remove FP asserts in VOP3 lane manip insts

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The VOP3 instruction encoding generally states that ABS/NEG modifiers in
the instruction encoding are only valid on floating point data types.
This is currently coded in gem5 to mean floating point *instructions*.
For untyped instructions like V_CNDMASK_B32, we don't actually know what
the data type is. We must trust that the compiler did not attempt to
apply these bits to non-FP data types.

This commit simply removes the asserts. The ABS/NEG modifiers are
therefore ignored which is consistent with the ISA documentation.
This is done on the lane manipulation instructions V_CNDMASK_B32,
V_READLINE_B32, and V_WRITELANE_B32 which are typically used to mask off
or move data between registers. Other bitwise instructions (e.g.,
V_OR_B32) keep the asserts as bitwise operations on FP types are
genernally illegal in languages like C++.

Change-Id: I478c5272ba96383a063b2828de21d60948b25c8f
This commit is contained in:
Matthew Poremba
2024-05-02 15:58:47 -07:00
parent 2703fb5699
commit 8249d6d1cd
1 changed files with 0 additions and 30 deletions
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30
src/arch/amdgpu/vega/insts/vop3.cc
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@@ -66,16 +66,6 @@ namespace VegaISA
src1.readSrc();
vcc.read();
/**
* input modifiers are supported by FP operations only
*/
assert(!(instData.ABS & 0x1));
assert(!(instData.ABS & 0x2));
assert(!(instData.ABS & 0x4));
assert(!(extData.NEG & 0x1));
assert(!(extData.NEG & 0x2));
assert(!(extData.NEG & 0x4));
for (int lane = 0; lane < NumVecElemPerVecReg; ++lane) {
if (wf->execMask(lane)) {
vdst[lane] = bits(vcc.rawData(), lane)
@@ -8440,16 +8430,6 @@ namespace VegaISA
src0.readSrc();
src1.read();
/**
* input modifiers are supported by FP operations only
*/
assert(!(instData.ABS & 0x1));
assert(!(instData.ABS & 0x2));
assert(!(instData.ABS & 0x4));
assert(!(extData.NEG & 0x1));
assert(!(extData.NEG & 0x2));
assert(!(extData.NEG & 0x4));
sdst = src0[src1.rawData() & 0x3f];
sdst.write();
@@ -8484,16 +8464,6 @@ namespace VegaISA
src1.read();
vdst.read();
/**
* input modifiers are supported by FP operations only
*/
assert(!(instData.ABS & 0x1));
assert(!(instData.ABS & 0x2));
assert(!(instData.ABS & 0x4));
assert(!(extData.NEG & 0x1));
assert(!(extData.NEG & 0x2));
assert(!(extData.NEG & 0x4));
vdst[src1.rawData() & 0x3f] = src0.rawData();
vdst.write();