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6727 - bugfix in a multiply instruction 

Also more error-detection for this case all across the toolchain.
This commit is contained in:
Kartik Agaram 2020-08-22 14:35:44 -07:00
parent db894e7968
commit 15b9880136
5 changed files with 10 additions and 6 deletions
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2
033check_operands.cc
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@ -379,7 +379,7 @@ void check_operands_modrm(const line& inst, const word& op) {
check_operand_metadata_present(inst, "mod", op);
check_operand_metadata_present(inst, "rm32", op);
// no check for r32; some instructions don't use it; just assume it's 0 if missing
if (op.data == "81" || op.data == "8f" || op.data == "ff") { // keep sync'd with 'help subop'
if (op.data == "81" || op.data == "8f" || op.data == "f7" || op.data == "ff") { // keep sync'd with 'help subop'
check_operand_metadata_present(inst, "subop", op);
check_operand_metadata_absent(inst, "r32", op, "should be replaced by subop");
}

2
121new-stream.subx
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@ -17,7 +17,7 @@ new-stream: # ad: (addr allocation-descriptor), length: int, elemsize: int, out
8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 0/r32/eax 0x10/disp8 . # copy *(ebp+16) to eax
# . eax *= length
31/xor 3/mod/direct 2/rm32/edx . . . 2/r32/edx . . # clear edx
f7 4/subop/multiply 1/mod/*+disp8 5/rm32/ebp . . 0xc/disp8 . # multiply *(ebp+12) into eax
f7 4/subop/multiply 1/mod/*+disp8 5/rm32/ebp . . 0xc/disp8 . # multiply *(ebp+12) into edx:eax
# . if overflow abort
81 7/subop/compare 3/mod/direct 2/rm32/edx . . . . . 0/imm32 # compare edx
75/jump-if-!= $new-stream:abort/disp8

5
308allocate-array.subx
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@ -6,12 +6,15 @@ allocate-array2: # ad: (addr allocation-descriptor), array-len: int, elem-size:
89/<- %ebp 4/r32/esp
# . save registers
50/push-eax
52/push-edx
#
8b/-> *(ebp+0xc) 0/r32/eax
f7 4/subop/multiply-into 0/r32/eax *(ebp+0x10)
f7 4/subop/multiply-into-eax-edx *(ebp+0x10)
# TODO: check edx for overflow
(allocate-array *(ebp+8) %eax *(ebp+0x14))
$allocate-array2:end:
# . restore registers
5a/pop-to-edx
58/pop-to-eax
# . epilogue
89/<- %esp 5/r32/ebp

BIN
apps/mu
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7
apps/mu.subx
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@ -14409,8 +14409,9 @@ size-of-array: # a: (addr type-tree) -> result/eax: int
8b/-> *(eax+8) 1/r32/ecx # Type-tree-value-size
# return 4 + array-size * size-of(elem-type)
(size-of-type-id-as-array-element %edx) # => eax
f7 4/subop/multiply-into-eax %ecx
f7 4/subop/multiply-into-edx-eax %ecx
05/add-to-eax 4/imm32 # for array size
# TODO: check edx for overflow
$size-of-array:end:
# . restore registers
5a/pop-to-edx
@ -16549,7 +16550,7 @@ $translate-mu-index-stmt-with-array-in-register:emit-literal-index:
89/<- %edx 0/r32/eax
# offset = idx-value * array-element-size(base->type)
(array-element-size %ebx *(ebp+0x10) *(ebp+0x14)) # => eax
f7 4/subop/multiply-into-eax %edx # clobbers edx
f7 4/subop/multiply-into-edx-eax %edx # clobbers edx
# offset += 4 for array size
05/add-to-eax 4/imm32
# TODO: check edx for overflow
@ -16666,7 +16667,7 @@ $translate-mu-index-stmt-with-array-on-stack:emit-literal-index:
89/<- %edx 0/r32/eax
# offset = idx-value * array-element-size(base)
(array-element-size %ecx *(ebp+0x10) *(ebp+0x14)) # => eax
f7 4/subop/multiply-into-eax %edx # clobbers edx
f7 4/subop/multiply-into-edx-eax %edx # clobbers edx
# offset += base->offset
03/add *(ecx+0x14) 0/r32/eax # Var-offset
# offset += 4 for array size