Implement x86 int <--> float. (128ad2d2) · Commits · e / os / android_system_core

libacc/acc.cpp

+65 −10

Original line number	Diff line number	Diff line
		@@ -532,7 +532,10 @@ class Compiler : public ErrorSink {
		}

		bool isFloatType(Type* pType) {
		TypeTag tag = pType->tag;
		return isFloatTag(pType->tag);
		}

		bool isFloatTag(TypeTag tag) {
		return tag == TY_FLOAT \|\| tag == TY_DOUBLE;
		}

		@@ -1283,6 +1286,9 @@ class Compiler : public ErrorSink {
		}

		virtual void loadR0(int ea, bool isIncDec, int op, Type* pType) {
		TypeTag tag = collapseType(pType->tag);
		switch (tag) {
		case TY_INT:
		gmov(8, ea); /* mov EA, %eax */
		if (isIncDec) {
		/* Implement post-increment or post decrement.
		@@ -1290,13 +1296,38 @@ class Compiler : public ErrorSink {
		gmov(0, ea); /* 83 ADD */
		o(decodeOp(op));
		}
		break;
		case TY_FLOAT:
		if (ea < -LOCAL \|\| ea > LOCAL) {
		oad(0x05d9, ea); // flds ea
		} else {
		oad(0x85d9, ea); // flds ea(%ebp)
		}
		if (isIncDec) {
		error("inc/dec not implemented for float.");
		}
		break;
		case TY_DOUBLE:
		if (ea < -LOCAL \|\| ea > LOCAL) {
		oad(0x05dd, ea); // fldl ea
		} else {
		oad(0x85dd, ea); // fldl ea(%ebp)
		}
		if (isIncDec) {
		error("inc/dec not implemented for double.");
		}
		break;
		default:
		error("Unable to load type %d", tag);
		break;
		}
		setR0Type(pType);
		}

		virtual void convertR0(Type* pType){
		Type* pR0Type = getR0Type();
		if (pR0Type == NULL) {
		error("don't know R0Type");
		assert(false);
		setR0Type(pType);
		return;
		}
		@@ -1304,10 +1335,34 @@ class Compiler : public ErrorSink {
		// do nothing special
		} else if (isFloatType(pType) && isFloatType(pR0Type)) {
		// do nothing special, both held in same register on x87.
		} else {
		TypeTag r0Tag = collapseType(pR0Type->tag);
		TypeTag destTag = collapseType(pType->tag);
		if (r0Tag == TY_INT && isFloatTag(destTag)) {
		// Convert R0 from int to float
		o(0x50); // push %eax
		o(0x2404DB); // fildl 0(%esp)
		o(0x58); // pop %eax
		} else if (isFloatTag(r0Tag) && destTag == TY_INT) {
		// Convert R0 from float to int. Complicated because
		// need to save and restore the rounding mode.
		o(0x50); // push %eax
		o(0x50); // push %eax
		o(0x02247cD9); // fnstcw 2(%esp)
		o(0x2444b70f); // movzwl 2(%esp), %eax
		o(0x02);
		o(0x0cb4); // movb $12, %ah
		o(0x24048966); // movw %ax, 0(%esp)
		o(0x242cd9); // fldcw 0(%esp)
		o(0x04245cdb); // fistpl 4(%esp)
		o(0x02246cd9); // fldcw 2(%esp)
		o(0x58); // pop %eax
		o(0x58); // pop %eax
		} else {
		error("Incompatible types old: %d new: %d",
		pR0Type->tag, pType->tag);
		}
		}
		setR0Type(pType);
		}

libacc/tests/data/float.c

+20 −2

Original line number	Diff line number	Diff line
		int ftoi(float f) {
		return f;
		}

		int dtoi(double d) {
		return d;
		}

		float itof(int i) {
		return i;
		}

		double itod(int i) {
		return i;
		}

		int main() {
		printf("int: %d float: %g double: %g\n", 1, 2.2f, 3.3);

		return 42;
		printf(" ftoi(1.4f)=%d\n", ftoi(1.4f));
		printf(" dtoi(2.4f)=%d\n", dtoi(2.4f));
		printf(" itof(3)=%g\n", itof(3));
		printf(" itod(4)=%g\n", itod(4));
		return 0;
		}