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bpf: simulator: correct div, mod insn semantics

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The div and mod eBPF instructions are unsigned, but the semantic
specification for the simulator incorrectly used signed operators.
Correct them to unsigned versions, and correct the ALU tests in
the simulator (which incorrectly assumed signed semantics).

Tested in bpf-unknown-none.

cpu/ChangeLog:
2020-09-08  David Faust  <david.faust@oracle.com>

	* bpf.cpu (define-alu-instructions): Correct semantic operators
	for div, mod to unsigned versions.

sim/ChangeLog:
2020-09-08  David Faust  <david.faust@oracle.com>

	* bpf/sem-be.c: Regenerate.
	* bpf/sem-le.c: Likewise.

sim/testsuite/ChangeLog:
2020-09-08  David Faust  <david.faust@oracle.com>

	* sim/bpf/alu.s: Correct div and mod tests.
	* sim/bpf/alu32.s: Likewise.
This commit is contained in:
David Faust 2020-09-08 11:39:07 -07:00
parent 790147a9e9
commit 3ad6c19423
8 changed files with 73 additions and 35 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
cpu/ChangeLog
View File

@ -1,3 +1,8 @@
2020-09-08 David Faust <david.faust@oracle.com>
* bpf.cpu (define-alu-instructions): Correct semantic operators
for div, mod to unsigned versions.
2020-09-01 Alan Modra <amodra@gmail.com>
* mep-core.cpu (f-8s8a2, f-12s4a2, f-17s16a2): Multiply signed

4
cpu/bpf.cpu
View File

@ -487,12 +487,12 @@
(daib add OP_CODE_ADD x-endian add)
(daib sub OP_CODE_SUB x-endian sub)
(daib mul OP_CODE_MUL x-endian mul)
(daib div OP_CODE_DIV x-endian div)
(daib div OP_CODE_DIV x-endian udiv)
(daib or OP_CODE_OR x-endian or)
(daib and OP_CODE_AND x-endian and)
(daib lsh OP_CODE_LSH x-endian sll)
(daib rsh OP_CODE_RSH x-endian srl)
(daib mod OP_CODE_MOD x-endian mod)
(daib mod OP_CODE_MOD x-endian umod)
(daib xor OP_CODE_XOR x-endian xor)
(daib arsh OP_CODE_ARSH x-endian sra)
(daiu neg OP_CODE_NEG x-endian neg)

5
sim/ChangeLog
View File

@ -1,3 +1,8 @@
2020-09-08 David Faust <david.faust@oracle.com>
* bpf/sem-be.c: Regenerate.
* bpf/sem-le.c: Likewise.
2020-09-03 Jose E. Marchesi <jose.marchesi@oracle.com>
* bpf/bpf.c: Include bpf-helpers.h.

16
sim/bpf/sem-be.c
View File

@ -461,7 +461,7 @@ SEM_FN_NAME (bpfbf_ebpfbe,divibe) (SIM_CPU *current_cpu, SEM_ARG sem_arg)
SEM_PC vpc = SEM_NEXT_VPC (sem_arg, pc, 8);
{
DI opval = DIVDI (CPU (h_gpr[FLD (f_dstbe)]), FLD (f_imm32));
DI opval = UDIVDI (CPU (h_gpr[FLD (f_dstbe)]), FLD (f_imm32));
CPU (h_gpr[FLD (f_dstbe)]) = opval;
CGEN_TRACE_RESULT (current_cpu, abuf, "gpr", 'D', opval);
}
@ -482,7 +482,7 @@ SEM_FN_NAME (bpfbf_ebpfbe,divrbe) (SIM_CPU *current_cpu, SEM_ARG sem_arg)
SEM_PC vpc = SEM_NEXT_VPC (sem_arg, pc, 8);
{
DI opval = DIVDI (CPU (h_gpr[FLD (f_dstbe)]), CPU (h_gpr[FLD (f_srcbe)]));
DI opval = UDIVDI (CPU (h_gpr[FLD (f_dstbe)]), CPU (h_gpr[FLD (f_srcbe)]));
CPU (h_gpr[FLD (f_dstbe)]) = opval;
CGEN_TRACE_RESULT (current_cpu, abuf, "gpr", 'D', opval);
}
@ -503,7 +503,7 @@ SEM_FN_NAME (bpfbf_ebpfbe,div32ibe) (SIM_CPU *current_cpu, SEM_ARG sem_arg)
SEM_PC vpc = SEM_NEXT_VPC (sem_arg, pc, 8);
{
USI opval = DIVSI (CPU (h_gpr[FLD (f_dstbe)]), FLD (f_imm32));
USI opval = UDIVSI (CPU (h_gpr[FLD (f_dstbe)]), FLD (f_imm32));
CPU (h_gpr[FLD (f_dstbe)]) = opval;
CGEN_TRACE_RESULT (current_cpu, abuf, "gpr", 'x', opval);
}
@ -524,7 +524,7 @@ SEM_FN_NAME (bpfbf_ebpfbe,div32rbe) (SIM_CPU *current_cpu, SEM_ARG sem_arg)
SEM_PC vpc = SEM_NEXT_VPC (sem_arg, pc, 8);
{
USI opval = DIVSI (CPU (h_gpr[FLD (f_dstbe)]), CPU (h_gpr[FLD (f_srcbe)]));
USI opval = UDIVSI (CPU (h_gpr[FLD (f_dstbe)]), CPU (h_gpr[FLD (f_srcbe)]));
CPU (h_gpr[FLD (f_dstbe)]) = opval;
CGEN_TRACE_RESULT (current_cpu, abuf, "gpr", 'x', opval);
}
@ -881,7 +881,7 @@ SEM_FN_NAME (bpfbf_ebpfbe,modibe) (SIM_CPU *current_cpu, SEM_ARG sem_arg)
SEM_PC vpc = SEM_NEXT_VPC (sem_arg, pc, 8);
{
DI opval = MODDI (CPU (h_gpr[FLD (f_dstbe)]), FLD (f_imm32));
DI opval = UMODDI (CPU (h_gpr[FLD (f_dstbe)]), FLD (f_imm32));
CPU (h_gpr[FLD (f_dstbe)]) = opval;
CGEN_TRACE_RESULT (current_cpu, abuf, "gpr", 'D', opval);
}
@ -902,7 +902,7 @@ SEM_FN_NAME (bpfbf_ebpfbe,modrbe) (SIM_CPU *current_cpu, SEM_ARG sem_arg)
SEM_PC vpc = SEM_NEXT_VPC (sem_arg, pc, 8);
{
DI opval = MODDI (CPU (h_gpr[FLD (f_dstbe)]), CPU (h_gpr[FLD (f_srcbe)]));
DI opval = UMODDI (CPU (h_gpr[FLD (f_dstbe)]), CPU (h_gpr[FLD (f_srcbe)]));
CPU (h_gpr[FLD (f_dstbe)]) = opval;
CGEN_TRACE_RESULT (current_cpu, abuf, "gpr", 'D', opval);
}
@ -923,7 +923,7 @@ SEM_FN_NAME (bpfbf_ebpfbe,mod32ibe) (SIM_CPU *current_cpu, SEM_ARG sem_arg)
SEM_PC vpc = SEM_NEXT_VPC (sem_arg, pc, 8);
{
USI opval = MODSI (CPU (h_gpr[FLD (f_dstbe)]), FLD (f_imm32));
USI opval = UMODSI (CPU (h_gpr[FLD (f_dstbe)]), FLD (f_imm32));
CPU (h_gpr[FLD (f_dstbe)]) = opval;
CGEN_TRACE_RESULT (current_cpu, abuf, "gpr", 'x', opval);
}
@ -944,7 +944,7 @@ SEM_FN_NAME (bpfbf_ebpfbe,mod32rbe) (SIM_CPU *current_cpu, SEM_ARG sem_arg)
SEM_PC vpc = SEM_NEXT_VPC (sem_arg, pc, 8);
{
USI opval = MODSI (CPU (h_gpr[FLD (f_dstbe)]), CPU (h_gpr[FLD (f_srcbe)]));
USI opval = UMODSI (CPU (h_gpr[FLD (f_dstbe)]), CPU (h_gpr[FLD (f_srcbe)]));
CPU (h_gpr[FLD (f_dstbe)]) = opval;
CGEN_TRACE_RESULT (current_cpu, abuf, "gpr", 'x', opval);
}

16
sim/bpf/sem-le.c
View File

@ -461,7 +461,7 @@ SEM_FN_NAME (bpfbf_ebpfle,divile) (SIM_CPU *current_cpu, SEM_ARG sem_arg)
SEM_PC vpc = SEM_NEXT_VPC (sem_arg, pc, 8);
{
DI opval = DIVDI (CPU (h_gpr[FLD (f_dstle)]), FLD (f_imm32));
DI opval = UDIVDI (CPU (h_gpr[FLD (f_dstle)]), FLD (f_imm32));
CPU (h_gpr[FLD (f_dstle)]) = opval;
CGEN_TRACE_RESULT (current_cpu, abuf, "gpr", 'D', opval);
}
@ -482,7 +482,7 @@ SEM_FN_NAME (bpfbf_ebpfle,divrle) (SIM_CPU *current_cpu, SEM_ARG sem_arg)
SEM_PC vpc = SEM_NEXT_VPC (sem_arg, pc, 8);
{
DI opval = DIVDI (CPU (h_gpr[FLD (f_dstle)]), CPU (h_gpr[FLD (f_srcle)]));
DI opval = UDIVDI (CPU (h_gpr[FLD (f_dstle)]), CPU (h_gpr[FLD (f_srcle)]));
CPU (h_gpr[FLD (f_dstle)]) = opval;
CGEN_TRACE_RESULT (current_cpu, abuf, "gpr", 'D', opval);
}
@ -503,7 +503,7 @@ SEM_FN_NAME (bpfbf_ebpfle,div32ile) (SIM_CPU *current_cpu, SEM_ARG sem_arg)
SEM_PC vpc = SEM_NEXT_VPC (sem_arg, pc, 8);
{
USI opval = DIVSI (CPU (h_gpr[FLD (f_dstle)]), FLD (f_imm32));
USI opval = UDIVSI (CPU (h_gpr[FLD (f_dstle)]), FLD (f_imm32));
CPU (h_gpr[FLD (f_dstle)]) = opval;
CGEN_TRACE_RESULT (current_cpu, abuf, "gpr", 'x', opval);
}
@ -524,7 +524,7 @@ SEM_FN_NAME (bpfbf_ebpfle,div32rle) (SIM_CPU *current_cpu, SEM_ARG sem_arg)
SEM_PC vpc = SEM_NEXT_VPC (sem_arg, pc, 8);
{
USI opval = DIVSI (CPU (h_gpr[FLD (f_dstle)]), CPU (h_gpr[FLD (f_srcle)]));
USI opval = UDIVSI (CPU (h_gpr[FLD (f_dstle)]), CPU (h_gpr[FLD (f_srcle)]));
CPU (h_gpr[FLD (f_dstle)]) = opval;
CGEN_TRACE_RESULT (current_cpu, abuf, "gpr", 'x', opval);
}
@ -881,7 +881,7 @@ SEM_FN_NAME (bpfbf_ebpfle,modile) (SIM_CPU *current_cpu, SEM_ARG sem_arg)
SEM_PC vpc = SEM_NEXT_VPC (sem_arg, pc, 8);
{
DI opval = MODDI (CPU (h_gpr[FLD (f_dstle)]), FLD (f_imm32));
DI opval = UMODDI (CPU (h_gpr[FLD (f_dstle)]), FLD (f_imm32));
CPU (h_gpr[FLD (f_dstle)]) = opval;
CGEN_TRACE_RESULT (current_cpu, abuf, "gpr", 'D', opval);
}
@ -902,7 +902,7 @@ SEM_FN_NAME (bpfbf_ebpfle,modrle) (SIM_CPU *current_cpu, SEM_ARG sem_arg)
SEM_PC vpc = SEM_NEXT_VPC (sem_arg, pc, 8);
{
DI opval = MODDI (CPU (h_gpr[FLD (f_dstle)]), CPU (h_gpr[FLD (f_srcle)]));
DI opval = UMODDI (CPU (h_gpr[FLD (f_dstle)]), CPU (h_gpr[FLD (f_srcle)]));
CPU (h_gpr[FLD (f_dstle)]) = opval;
CGEN_TRACE_RESULT (current_cpu, abuf, "gpr", 'D', opval);
}
@ -923,7 +923,7 @@ SEM_FN_NAME (bpfbf_ebpfle,mod32ile) (SIM_CPU *current_cpu, SEM_ARG sem_arg)
SEM_PC vpc = SEM_NEXT_VPC (sem_arg, pc, 8);
{
USI opval = MODSI (CPU (h_gpr[FLD (f_dstle)]), FLD (f_imm32));
USI opval = UMODSI (CPU (h_gpr[FLD (f_dstle)]), FLD (f_imm32));
CPU (h_gpr[FLD (f_dstle)]) = opval;
CGEN_TRACE_RESULT (current_cpu, abuf, "gpr", 'x', opval);
}
@ -944,7 +944,7 @@ SEM_FN_NAME (bpfbf_ebpfle,mod32rle) (SIM_CPU *current_cpu, SEM_ARG sem_arg)
SEM_PC vpc = SEM_NEXT_VPC (sem_arg, pc, 8);
{
USI opval = MODSI (CPU (h_gpr[FLD (f_dstle)]), CPU (h_gpr[FLD (f_srcle)]));
USI opval = UMODSI (CPU (h_gpr[FLD (f_dstle)]), CPU (h_gpr[FLD (f_srcle)]));
CPU (h_gpr[FLD (f_dstle)]) = opval;
CGEN_TRACE_RESULT (current_cpu, abuf, "gpr", 'x', opval);
}

5
sim/testsuite/ChangeLog
View File

@ -1,3 +1,8 @@
2020-09-08 David Faust <david.faust@oracle.com>
* sim/bpf/alu.s: Correct div and mod tests.
* sim/bpf/alu32.s: Likewise.
2020-08-04 David Faust <david.faust@oracle.com>
Jose E. Marchesi <jose.marchesi@oracle.com>

26
sim/testsuite/sim/bpf/alu.s
View File

@ -40,11 +40,16 @@ main:
;; div
div %r2, %r1
fail_ne %r2, 0
div %r1, -10000
fail_ne %r1, -11007531
div %r1, 10000
fail_ne %r1, 11007531
div %r1, %r1
fail_ne %r1, 1
;; div is unsigned
lddw %r1, -8
div %r1, 2
fail_ne %r1, 0x7ffffffffffffffc ; sign bits NOT maintained - large pos.
;; and
lddw %r1, 0xaaaaaaaa55555555
and %r1, 0x55aaaaaa ; we still only have 32-bit imm.
@ -84,14 +89,21 @@ main:
;; mod
mov %r1, 1025
mod %r1, -16
mod %r1, 16
fail_ne %r1, 1
;; mod is unsigned
mov %r1, 1025
mod %r1, -16 ; mod unsigned -> will treat as large positive
fail_ne %r1, 1025
mov %r1, -25 ; -25 is 0xff..ffe7
mov %r2, 5 ; ... which when unsigned is a large positive
mod %r1, %r2 ; ... which is not evenly divisible by 5
fail_ne %r1, 1
mov %r1, -25
mov %r2, 5
mod %r1, %r2
fail_ne %r1, 0
;; xor
mov %r1, 0
xor %r1, %r2
fail_ne %r1, 5
xor %r1, 0x7eadbeef

31
sim/testsuite/sim/bpf/alu32.s
View File

@ -31,10 +31,15 @@ main:
fail_ne32 %r1, 264
;; div
div32 %r1, %r2 ; r1 /= r2 (r1 = 264 / -6 = -44)
div32 %r1, -2 ; r1 /= -2 (r1 = 22)
div32 %r1, 2 ; r1 /= 2 (r1 = 11)
fail_ne32 %r1, 11
div32 %r1, 6
mov32 %r2, 11
div32 %r1, %r2
fail_ne32 %r1, 4
;; div is unsigned
mov32 %r1, -8 ; 0xfffffff8
div32 %r1, 2
fail_ne32 %r1, 0x7ffffffc ; sign bits are not preserved
;; and (bitwise)
mov32 %r1, 0xb ; r1 = (0xb = 0b1011)
@ -70,13 +75,19 @@ main:
; i.e. upper-32 bits should be untouched
;; mod
mov32 %r1, -25
mov32 %r2, 4
mov32 %r1, 1025
mod32 %r1, 16
fail_ne32 %r1, 1
;; mod is unsigned
mov32 %r1, 1025
mod32 %r1, -16 ; when unsigned, much larger than 1025
fail_ne32 %r1, 1025
mov32 %r1, -25 ; when unsigned, a large positive which is
mov32 %r2, 5 ; ... not evenly divisible by 5
mod32 %r1, %r2
fail_ne32 %r1, -1
mov32 %r1, 25
mod32 %r1, 5
fail_ne32 %r1, 0
fail_ne32 %r1, 1
;; xor
xor32 %r1, %r2