JIT: Dump BB in/out memory SSAs inline when SSA is valid #95017

jakobbotsch · 2023-11-20T16:39:16Z

When SSA is considered to be valid, write in and out SSA numbers for memory states when dumping the blocks.

For example:

public static void Foo(C c)
{
    if (c.V % 2 == 0)
    {
        c.V = 123;
    }
    else
    {
        c.V = 456;
    }

    Console.WriteLine(c.V);
}

public class C
{
    public int V;
}

dumps

------------ BB01 [000..00A) -> BB03 (cond), preds={} succs={BB02,BB03}
ByrefExposed, GcHeap = m:1

***** BB01
STMT00000 ( 0x000[E-] ... 0x008 )
N009 ( 10, 10) [000007] ---XG------                         ▌  JTRUE     void
N008 (  8,  8) [000006] J--XG--N---                         └──▌  NE        int
N006 (  6,  6) [000004] ---XG------                            ├──▌  AND       int
N004 (  4,  4) [000002] ---XG------                            │  ├──▌  IND       int
N003 (  2,  2) [000024] -------N---                            │  │  └──▌  ADD       byref
N001 (  1,  1) [000000] -----------                            │  │     ├──▌  LCL_VAR   ref    V00 arg0         u:1
N002 (  1,  1) [000023] -----------                            │  │     └──▌  CNS_INT   long   8 Fseq[V]
N005 (  1,  1) [000003] -----------                            │  └──▌  CNS_INT   int    1
N007 (  1,  1) [000005] -----------                            └──▌  CNS_INT   int    0

ByrefExposed, GcHeap = m:1

------------ BB02 [00A..014) -> BB04 (always), preds={BB01} succs={BB04}
ByrefExposed, GcHeap = m:1

***** BB02
STMT00004 ( 0x00A[E-] ... 0x00D )
N005 (  6,  6) [000020] -A-XG------                         ▌  STOREIND  int
N003 (  2,  2) [000028] -------N---                         ├──▌  ADD       byref
N001 (  1,  1) [000017] -----------                         │  ├──▌  LCL_VAR   ref    V00 arg0         u:1
N002 (  1,  1) [000027] -----------                         │  └──▌  CNS_INT   long   8 Fseq[V]
N004 (  1,  1) [000018] -----------                         └──▌  CNS_INT   int    123

ByrefExposed, GcHeap = m:5

------------ BB03 [014..01F), preds={BB01} succs={BB04}
ByrefExposed, GcHeap = m:1

***** BB03
STMT00001 ( 0x014[E-] ... 0x01A )
N005 (  6,  9) [000011] -A-XG------                         ▌  STOREIND  int
N003 (  2,  2) [000026] -------N---                         ├──▌  ADD       byref
N001 (  1,  1) [000008] -----------                         │  ├──▌  LCL_VAR   ref    V00 arg0         u:1
N002 (  1,  1) [000025] -----------                         │  └──▌  CNS_INT   long   8 Fseq[V]
N004 (  1,  4) [000009] -----------                         └──▌  CNS_INT   int    456

ByrefExposed, GcHeap = m:4

------------ BB04 [01F..02B) (return), preds={BB02,BB03} succs={}
ByrefExposed, GcHeap = phi(m:5, m:4)

***** BB04
STMT00002 ( 0x01F[E-] ... 0x02A )
N005 ( 18, 10) [000015] --CXG------                         ▌  CALL      void   System.Console:WriteLine(int)
N004 (  4,  4) [000014] ---XG------ arg0 in rcx             └──▌  IND       int
N003 (  2,  2) [000030] -------N---                            └──▌  ADD       byref
N001 (  1,  1) [000012] -----------                               ├──▌  LCL_VAR   ref    V00 arg0         u:1 (last use)
N002 (  1,  1) [000029] -----------                               └──▌  CNS_INT   long   8 Fseq[V]

***** BB04
STMT00003 ( 0x02A[E-] ... ??? )
N001 (  0,  0) [000016] -----------                         ▌  RETURN    void

ByrefExposed, GcHeap = m:3

after SSA.

When SSA is considered to be valid, write in and out SSA numbers for memory states when dumping the blocks. For example: ```csharp public static void Foo(C c) { if (c.V % 2 == 0) { c.V = 123; } else { c.V = 456; } Console.WriteLine(c.V); } public class C { public int V; } ``` dumps ``` ------------ BB01 [000..00A) -> BB03 (cond), preds={} succs={BB02,BB03} ByrefExposed, GcHeap = m:1 ***** BB01 STMT00000 ( 0x000[E-] ... 0x008 ) N009 ( 10, 10) [000007] ---XG------ ▌ JTRUE void N008 ( 8, 8) [000006] J--XG--N--- └──▌ NE int N006 ( 6, 6) [000004] ---XG------ ├──▌ AND int N004 ( 4, 4) [000002] ---XG------ │ ├──▌ IND int N003 ( 2, 2) [000024] -------N--- │ │ └──▌ ADD byref N001 ( 1, 1) [000000] ----------- │ │ ├──▌ LCL_VAR ref V00 arg0 u:1 N002 ( 1, 1) [000023] ----------- │ │ └──▌ CNS_INT long 8 Fseq[V] N005 ( 1, 1) [000003] ----------- │ └──▌ CNS_INT int 1 N007 ( 1, 1) [000005] ----------- └──▌ CNS_INT int 0 ByrefExposed, GcHeap = m:1 ------------ BB02 [00A..014) -> BB04 (always), preds={BB01} succs={BB04} ByrefExposed, GcHeap = m:1 ***** BB02 STMT00004 ( 0x00A[E-] ... 0x00D ) N005 ( 6, 6) [000020] -A-XG------ ▌ STOREIND int N003 ( 2, 2) [000028] -------N--- ├──▌ ADD byref N001 ( 1, 1) [000017] ----------- │ ├──▌ LCL_VAR ref V00 arg0 u:1 N002 ( 1, 1) [000027] ----------- │ └──▌ CNS_INT long 8 Fseq[V] N004 ( 1, 1) [000018] ----------- └──▌ CNS_INT int 123 ByrefExposed, GcHeap = m:5 ------------ BB03 [014..01F), preds={BB01} succs={BB04} ByrefExposed, GcHeap = m:1 ***** BB03 STMT00001 ( 0x014[E-] ... 0x01A ) N005 ( 6, 9) [000011] -A-XG------ ▌ STOREIND int N003 ( 2, 2) [000026] -------N--- ├──▌ ADD byref N001 ( 1, 1) [000008] ----------- │ ├──▌ LCL_VAR ref V00 arg0 u:1 N002 ( 1, 1) [000025] ----------- │ └──▌ CNS_INT long 8 Fseq[V] N004 ( 1, 4) [000009] ----------- └──▌ CNS_INT int 456 ByrefExposed, GcHeap = m:4 ------------ BB04 [01F..02B) (return), preds={BB02,BB03} succs={} ByrefExposed, GcHeap = phi(m:5, m:4) ***** BB04 STMT00002 ( 0x01F[E-] ... 0x02A ) N005 ( 18, 10) [000015] --CXG------ ▌ CALL void System.Console:WriteLine(int) N004 ( 4, 4) [000014] ---XG------ arg0 in rcx └──▌ IND int N003 ( 2, 2) [000030] -------N--- └──▌ ADD byref N001 ( 1, 1) [000012] ----------- ├──▌ LCL_VAR ref V00 arg0 u:1 (last use) N002 ( 1, 1) [000029] ----------- └──▌ CNS_INT long 8 Fseq[V] ***** BB04 STMT00003 ( 0x02A[E-] ... ??? ) N001 ( 0, 0) [000016] ----------- ▌ RETURN void ByrefExposed, GcHeap = m:3 ``` after SSA.

ghost · 2023-11-20T16:39:30Z

Tagging subscribers to this area: @JulieLeeMSFT, @jakobbotsch
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Issue Details

When SSA is considered to be valid, write in and out SSA numbers for memory states when dumping the blocks.

For example:

public static void Foo(C c)
{
    if (c.V % 2 == 0)
    {
        c.V = 123;
    }
    else
    {
        c.V = 456;
    }

    Console.WriteLine(c.V);
}

public class C
{
    public int V;
}

dumps

------------ BB01 [000..00A) -> BB03 (cond), preds={} succs={BB02,BB03}
ByrefExposed, GcHeap = m:1

***** BB01
STMT00000 ( 0x000[E-] ... 0x008 )
N009 ( 10, 10) [000007] ---XG------                         ▌  JTRUE     void
N008 (  8,  8) [000006] J--XG--N---                         └──▌  NE        int
N006 (  6,  6) [000004] ---XG------                            ├──▌  AND       int
N004 (  4,  4) [000002] ---XG------                            │  ├──▌  IND       int
N003 (  2,  2) [000024] -------N---                            │  │  └──▌  ADD       byref
N001 (  1,  1) [000000] -----------                            │  │     ├──▌  LCL_VAR   ref    V00 arg0         u:1
N002 (  1,  1) [000023] -----------                            │  │     └──▌  CNS_INT   long   8 Fseq[V]
N005 (  1,  1) [000003] -----------                            │  └──▌  CNS_INT   int    1
N007 (  1,  1) [000005] -----------                            └──▌  CNS_INT   int    0

ByrefExposed, GcHeap = m:1

------------ BB02 [00A..014) -> BB04 (always), preds={BB01} succs={BB04}
ByrefExposed, GcHeap = m:1

***** BB02
STMT00004 ( 0x00A[E-] ... 0x00D )
N005 (  6,  6) [000020] -A-XG------                         ▌  STOREIND  int
N003 (  2,  2) [000028] -------N---                         ├──▌  ADD       byref
N001 (  1,  1) [000017] -----------                         │  ├──▌  LCL_VAR   ref    V00 arg0         u:1
N002 (  1,  1) [000027] -----------                         │  └──▌  CNS_INT   long   8 Fseq[V]
N004 (  1,  1) [000018] -----------                         └──▌  CNS_INT   int    123

ByrefExposed, GcHeap = m:5

------------ BB03 [014..01F), preds={BB01} succs={BB04}
ByrefExposed, GcHeap = m:1

***** BB03
STMT00001 ( 0x014[E-] ... 0x01A )
N005 (  6,  9) [000011] -A-XG------                         ▌  STOREIND  int
N003 (  2,  2) [000026] -------N---                         ├──▌  ADD       byref
N001 (  1,  1) [000008] -----------                         │  ├──▌  LCL_VAR   ref    V00 arg0         u:1
N002 (  1,  1) [000025] -----------                         │  └──▌  CNS_INT   long   8 Fseq[V]
N004 (  1,  4) [000009] -----------                         └──▌  CNS_INT   int    456

ByrefExposed, GcHeap = m:4

------------ BB04 [01F..02B) (return), preds={BB02,BB03} succs={}
ByrefExposed, GcHeap = phi(m:5, m:4)

***** BB04
STMT00002 ( 0x01F[E-] ... 0x02A )
N005 ( 18, 10) [000015] --CXG------                         ▌  CALL      void   System.Console:WriteLine(int)
N004 (  4,  4) [000014] ---XG------ arg0 in rcx             └──▌  IND       int
N003 (  2,  2) [000030] -------N---                            └──▌  ADD       byref
N001 (  1,  1) [000012] -----------                               ├──▌  LCL_VAR   ref    V00 arg0         u:1 (last use)
N002 (  1,  1) [000029] -----------                               └──▌  CNS_INT   long   8 Fseq[V]

***** BB04
STMT00003 ( 0x02A[E-] ... ??? )
N001 (  0,  0) [000016] -----------                         ▌  RETURN    void

ByrefExposed, GcHeap = m:3

after SSA.

Author:	jakobbotsch
Assignees:	jakobbotsch
Labels:	`area-CodeGen-coreclr`
Milestone:	-

jakobbotsch · 2023-11-20T20:31:19Z

cc @dotnet/jit-contrib

superpmi-replay failure is #95025

BruceForstall

One suggestion is to prefix the output by a distinguished tag (e.g., "SSA MEM: ") so it's super obvious what the output is about (and is searchable). E.g., from your example:

------------ BB01 [000..00A) -> BB03 (cond), preds={} succs={BB02,BB03}
SSA MEM: ByrefExposed, GcHeap = m:1

***** BB01
STMT00000 ( 0x000[E-] ... 0x008 )
N009 ( 10, 10) [000007] ---XG------                         ▌  JTRUE     void
N008 (  8,  8) [000006] J--XG--N---                         └──▌  NE        int
N006 (  6,  6) [000004] ---XG------                            ├──▌  AND       int
N004 (  4,  4) [000002] ---XG------                            │  ├──▌  IND       int
N003 (  2,  2) [000024] -------N---                            │  │  └──▌  ADD       byref
N001 (  1,  1) [000000] -----------                            │  │     ├──▌  LCL_VAR   ref    V00 arg0         u:1
N002 (  1,  1) [000023] -----------                            │  │     └──▌  CNS_INT   long   8 Fseq[V]
N005 (  1,  1) [000003] -----------                            │  └──▌  CNS_INT   int    1
N007 (  1,  1) [000005] -----------                            └──▌  CNS_INT   int    0

SSA MEM: ByrefExposed, GcHeap = m:1

------------ BB02 [00A..014) -> BB04 (always), preds={BB01} succs={BB04}
SSA MEM: ByrefExposed, GcHeap = m:1

***** BB02
STMT00004 ( 0x00A[E-] ... 0x00D )
N005 (  6,  6) [000020] -A-XG------                         ▌  STOREIND  int
N003 (  2,  2) [000028] -------N---                         ├──▌  ADD       byref
N001 (  1,  1) [000017] -----------                         │  ├──▌  LCL_VAR   ref    V00 arg0         u:1
N002 (  1,  1) [000027] -----------                         │  └──▌  CNS_INT   long   8 Fseq[V]
N004 (  1,  1) [000018] -----------                         └──▌  CNS_INT   int    123

SSA MEM: ByrefExposed, GcHeap = m:5

ghost assigned jakobbotsch Nov 20, 2023

dotnet-issue-labeler bot added the area-CodeGen-coreclr CLR JIT compiler in src/coreclr/src/jit and related components such as SuperPMI label Nov 20, 2023

BruceForstall approved these changes Nov 21, 2023

View reviewed changes

Print prefix suggested in review

2803ed0

jakobbotsch merged commit 186cf81 into dotnet:main Nov 21, 2023

jakobbotsch deleted the ssa-ir-dump branch November 21, 2023 13:33

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JIT: Dump BB in/out memory SSAs inline when SSA is valid #95017

JIT: Dump BB in/out memory SSAs inline when SSA is valid #95017

jakobbotsch commented Nov 20, 2023

ghost commented Nov 20, 2023

jakobbotsch commented Nov 20, 2023

BruceForstall left a comment

JIT: Dump BB in/out memory SSAs inline when SSA is valid #95017

JIT: Dump BB in/out memory SSAs inline when SSA is valid #95017

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jakobbotsch commented Nov 20, 2023

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