From 4c0f1c402fee72a4b57cfb0dde9870265eab622a Mon Sep 17 00:00:00 2001 From: Michael Pavone Date: Mon, 28 Jan 2019 22:37:46 -0800 Subject: Fixed flag calculation for sub instructions in CPU DSL --- cpu_dsl.py | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) (limited to 'cpu_dsl.py') diff --git a/cpu_dsl.py b/cpu_dsl.py index 99d94d8..3bef9e7 100755 --- a/cpu_dsl.py +++ b/cpu_dsl.py @@ -240,8 +240,8 @@ class Op: decl,name = prog.getTemp(size) dst = prog.carryFlowDst = name prog.lastA = a - prog.lastB = '(-' + b + ')' if op == '-' else b - prog.lastWasSub = op == '-' + prog.lastB = b + prog.lastBFlow = '(-' + b + ')' if op == '-' else b else: dst = params[2] return decl + '\n\t{dst} = {a} {op} {b};'.format( @@ -313,11 +313,10 @@ def _updateFlagsCImpl(prog, params, rawParams): resultBit = prog.paramSize(prog.lastDst) elif calc == 'half': resultBit = 4 - fmt = '({a} ^ {b} ^ ~{res})' if prog.lastWasSub else '({a} ^ {b} ^ {res})' - myRes = fmt.format(a = prog.lastA, b = prog.lastB, res = lastDst) + myRes = '({a} ^ {b} ^ {res})'.format(a = prog.lastA, b = prog.lastB, res = lastDst) elif calc == 'overflow': resultBit = prog.paramSize(prog.lastDst) - 1 - myRes = '((~({a} ^ {b})) & ({a} ^ {res}))'.format(a = prog.lastA, b = prog.lastB, res = lastDst) + myRes = '((~({a} ^ {b})) & ({a} ^ {res}))'.format(a = prog.lastA, b = prog.lastBFlow, res = lastDst) else: resultBit = int(resultBit) if type(storage) is tuple: @@ -991,7 +990,7 @@ class Program: self.carryFlowDst = None self.lastA = None self.lastB = None - self.lastWasSub = False + self.lastBFlow = None def __str__(self): pieces = [] -- cgit v1.2.3