Assertion failed '!"Duplicate gtTreeID was found"' during 'Importation'

[kunalspathak]

Repro file:

TestClass22-test-assertion.g.cs.txt

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Issue Details

---

Repro file:

TestClass22-test-assertion.g.cs.txt

Author:	kunalspathak
Assignees:	-
Labels:	os-windows, arch-x64, area-CodeGen-coreclr, arch-avx512
Milestone:	-

[JulieLeeMSFT]

@AndyAyersMS, PTAL.

[AndyAyersMS]

We have two uses of [042010]:

***** BB261
STMT07182 ( ??? ... ??? )
               [042021] -----------                         *  COMMA     void  
               [042010] -----------                         +--*  CNS_VEC   simd64<0x0000000000000000, 0x0000000000000000, 0x0000000000000000, 0x0000000000000000, 0x0000000000000000, 0x0000000000000000, 0x0000000000000000, 0x0000000000000000>
               [042020] -----------                         \--*  NOP       void 

***** BB261
STMT07185 ( ??? ... ??? )
               [042034] DA--G------                         *  STORE_LCL_VAR simd64 V4582 tmp3814    
               [042022] ----G------                         \--*  HWINTRINSIC simd64 double TernaryLogic
               [042010] -----------                            +--*  CNS_VEC   simd64<0x0000000000000000, 0x0000000000000000, 0x0000000000000000, 0x0000000000000000, 0x0000000000000000, 0x0000000000000000, 0x0000000000000000, 0x0000000000000000>
               [042019] -----------                            +--*  LCL_VAR   simd64 V4577 tmp3809    
               [042012] n---G------                            +--*  IND       simd64
               [042011] H----------                            |  \--*  CNS_INT(h) long   0x21d00209410 static Fseq[s_v512_double_46]
               [042013] -----------                            \--*  CNS_INT   int    17

In handling the ternary HW intrinsic there are several bits of logic that try and save creating a new zero operand:

                            assert(unusedVal1);

                            if (!(*val1)->IsVectorZero())
                            {
                                *val1 = gtNewZeroConNode(retType);
                            }

However those operands have been forcibly spilled (see first stmt above) and so can't be reused later on.

We should either make the spilling logic smarter (and not spill nodes we can reuse) or else just make new zeros later on always.

This code was introduced in #85833. cc @tannergooding

[AndyAyersMS]

Potential fix

diff --git a/src/coreclr/jit/hwintrinsicxarch.cpp b/src/coreclr/jit/hwintrinsicxarch.cpp
index 488f65b5ac0..065999982a8 100644
--- a/src/coreclr/jit/hwintrinsicxarch.cpp
+++ b/src/coreclr/jit/hwintrinsicxarch.cpp
@@ -3602,17 +3602,19 @@ GenTree* Compiler::impSpecialIntrinsic(NamedIntrinsic        intrinsic,
                     op2 = impSIMDPopStack();
                     op1 = impSIMDPopStack();

-                    if (unusedVal1)
+                    // Consume operands we won't use, in case they have side effects.
+                    //
+                    if (unusedVal1 && !(*val1)->IsVectorZero())
                     {
                         impAppendTree(gtUnusedValNode(*val1), CHECK_SPILL_ALL, impCurStmtDI);
                     }

-                    if (unusedVal2)
+                    if (unusedVal2 && !(*val2)->IsVectorZero())
                     {
                         impAppendTree(gtUnusedValNode(*val2), CHECK_SPILL_ALL, impCurStmtDI);
                     }

-                    if (unusedVal3)
+                    if (unusedVal3 && !(*val3)->IsVectorZero())
                     {
                         impAppendTree(gtUnusedValNode(*val3), CHECK_SPILL_ALL, impCurStmtDI);
                     }

this gets us past the assert, but compilation fails later with what looks like ##90508:

Assert failure(PID 9448 [0x000024e8], Thread: 1472 [0x05c0]): Assertion failed 'hwintrinsicChild->isContained()' in 'TestClass:Method3(TestClass+S1,TestClass+S1,byref,byref,byref,byref):TestClass+S2:this' during 'Generate code' (IL size 1000600; hash 0x713b0a92; Tier0-FullOpts-MinOpts)

    File: C:\repos\runtime0\src\coreclr\jit\instr.cpp Line: 858