JavaScriptCore/assembler/ARMAssembler.cpp
changeset 0 4f2f89ce4247
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/JavaScriptCore/assembler/ARMAssembler.cpp	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,378 @@
+/*
+ * Copyright (C) 2009 University of Szeged
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY UNIVERSITY OF SZEGED ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL UNIVERSITY OF SZEGED OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+
+#if ENABLE(ASSEMBLER) && CPU(ARM_TRADITIONAL)
+
+#include "ARMAssembler.h"
+
+namespace JSC {
+
+// Patching helpers
+
+void ARMAssembler::patchConstantPoolLoad(void* loadAddr, void* constPoolAddr)
+{
+    ARMWord *ldr = reinterpret_cast<ARMWord*>(loadAddr);
+    ARMWord diff = reinterpret_cast<ARMWord*>(constPoolAddr) - ldr;
+    ARMWord index = (*ldr & 0xfff) >> 1;
+
+    ASSERT(diff >= 1);
+    if (diff >= 2 || index > 0) {
+        diff = (diff + index - 2) * sizeof(ARMWord);
+        ASSERT(diff <= 0xfff);
+        *ldr = (*ldr & ~0xfff) | diff;
+    } else
+        *ldr = (*ldr & ~(0xfff | ARMAssembler::DT_UP)) | sizeof(ARMWord);
+}
+
+// Handle immediates
+
+ARMWord ARMAssembler::getOp2(ARMWord imm)
+{
+    int rol;
+
+    if (imm <= 0xff)
+        return OP2_IMM | imm;
+
+    if ((imm & 0xff000000) == 0) {
+        imm <<= 8;
+        rol = 8;
+    }
+    else {
+        imm = (imm << 24) | (imm >> 8);
+        rol = 0;
+    }
+
+    if ((imm & 0xff000000) == 0) {
+        imm <<= 8;
+        rol += 4;
+    }
+
+    if ((imm & 0xf0000000) == 0) {
+        imm <<= 4;
+        rol += 2;
+    }
+
+    if ((imm & 0xc0000000) == 0) {
+        imm <<= 2;
+        rol += 1;
+    }
+
+    if ((imm & 0x00ffffff) == 0)
+        return OP2_IMM | (imm >> 24) | (rol << 8);
+
+    return INVALID_IMM;
+}
+
+int ARMAssembler::genInt(int reg, ARMWord imm, bool positive)
+{
+    // Step1: Search a non-immediate part
+    ARMWord mask;
+    ARMWord imm1;
+    ARMWord imm2;
+    int rol;
+
+    mask = 0xff000000;
+    rol = 8;
+    while(1) {
+        if ((imm & mask) == 0) {
+            imm = (imm << rol) | (imm >> (32 - rol));
+            rol = 4 + (rol >> 1);
+            break;
+        }
+        rol += 2;
+        mask >>= 2;
+        if (mask & 0x3) {
+            // rol 8
+            imm = (imm << 8) | (imm >> 24);
+            mask = 0xff00;
+            rol = 24;
+            while (1) {
+                if ((imm & mask) == 0) {
+                    imm = (imm << rol) | (imm >> (32 - rol));
+                    rol = (rol >> 1) - 8;
+                    break;
+                }
+                rol += 2;
+                mask >>= 2;
+                if (mask & 0x3)
+                    return 0;
+            }
+            break;
+        }
+    }
+
+    ASSERT((imm & 0xff) == 0);
+
+    if ((imm & 0xff000000) == 0) {
+        imm1 = OP2_IMM | ((imm >> 16) & 0xff) | (((rol + 4) & 0xf) << 8);
+        imm2 = OP2_IMM | ((imm >> 8) & 0xff) | (((rol + 8) & 0xf) << 8);
+    } else if (imm & 0xc0000000) {
+        imm1 = OP2_IMM | ((imm >> 24) & 0xff) | ((rol & 0xf) << 8);
+        imm <<= 8;
+        rol += 4;
+
+        if ((imm & 0xff000000) == 0) {
+            imm <<= 8;
+            rol += 4;
+        }
+
+        if ((imm & 0xf0000000) == 0) {
+            imm <<= 4;
+            rol += 2;
+        }
+
+        if ((imm & 0xc0000000) == 0) {
+            imm <<= 2;
+            rol += 1;
+        }
+
+        if ((imm & 0x00ffffff) == 0)
+            imm2 = OP2_IMM | (imm >> 24) | ((rol & 0xf) << 8);
+        else
+            return 0;
+    } else {
+        if ((imm & 0xf0000000) == 0) {
+            imm <<= 4;
+            rol += 2;
+        }
+
+        if ((imm & 0xc0000000) == 0) {
+            imm <<= 2;
+            rol += 1;
+        }
+
+        imm1 = OP2_IMM | ((imm >> 24) & 0xff) | ((rol & 0xf) << 8);
+        imm <<= 8;
+        rol += 4;
+
+        if ((imm & 0xf0000000) == 0) {
+            imm <<= 4;
+            rol += 2;
+        }
+
+        if ((imm & 0xc0000000) == 0) {
+            imm <<= 2;
+            rol += 1;
+        }
+
+        if ((imm & 0x00ffffff) == 0)
+            imm2 = OP2_IMM | (imm >> 24) | ((rol & 0xf) << 8);
+        else
+            return 0;
+    }
+
+    if (positive) {
+        mov_r(reg, imm1);
+        orr_r(reg, reg, imm2);
+    } else {
+        mvn_r(reg, imm1);
+        bic_r(reg, reg, imm2);
+    }
+
+    return 1;
+}
+
+ARMWord ARMAssembler::getImm(ARMWord imm, int tmpReg, bool invert)
+{
+    ARMWord tmp;
+
+    // Do it by 1 instruction
+    tmp = getOp2(imm);
+    if (tmp != INVALID_IMM)
+        return tmp;
+
+    tmp = getOp2(~imm);
+    if (tmp != INVALID_IMM) {
+        if (invert)
+            return tmp | OP2_INV_IMM;
+        mvn_r(tmpReg, tmp);
+        return tmpReg;
+    }
+
+    return encodeComplexImm(imm, tmpReg);
+}
+
+void ARMAssembler::moveImm(ARMWord imm, int dest)
+{
+    ARMWord tmp;
+
+    // Do it by 1 instruction
+    tmp = getOp2(imm);
+    if (tmp != INVALID_IMM) {
+        mov_r(dest, tmp);
+        return;
+    }
+
+    tmp = getOp2(~imm);
+    if (tmp != INVALID_IMM) {
+        mvn_r(dest, tmp);
+        return;
+    }
+
+    encodeComplexImm(imm, dest);
+}
+
+ARMWord ARMAssembler::encodeComplexImm(ARMWord imm, int dest)
+{
+#if WTF_ARM_ARCH_AT_LEAST(7)
+    ARMWord tmp = getImm16Op2(imm);
+    if (tmp != INVALID_IMM) {
+        movw_r(dest, tmp);
+        return dest;
+    }
+    movw_r(dest, getImm16Op2(imm & 0xffff));
+    movt_r(dest, getImm16Op2(imm >> 16));
+    return dest;
+#else
+    // Do it by 2 instruction
+    if (genInt(dest, imm, true))
+        return dest;
+    if (genInt(dest, ~imm, false))
+        return dest;
+
+    ldr_imm(dest, imm);
+    return dest;
+#endif
+}
+
+// Memory load/store helpers
+
+void ARMAssembler::dataTransfer32(bool isLoad, RegisterID srcDst, RegisterID base, int32_t offset, bool bytes)
+{
+    ARMWord transferFlag = bytes ? DT_BYTE : 0;
+    if (offset >= 0) {
+        if (offset <= 0xfff)
+            dtr_u(isLoad, srcDst, base, offset | transferFlag);
+        else if (offset <= 0xfffff) {
+            add_r(ARMRegisters::S0, base, OP2_IMM | (offset >> 12) | (10 << 8));
+            dtr_u(isLoad, srcDst, ARMRegisters::S0, (offset & 0xfff) | transferFlag);
+        } else {
+            moveImm(offset, ARMRegisters::S0);
+            dtr_ur(isLoad, srcDst, base, ARMRegisters::S0 | transferFlag);
+        }
+    } else {
+        offset = -offset;
+        if (offset <= 0xfff)
+            dtr_d(isLoad, srcDst, base, offset | transferFlag);
+        else if (offset <= 0xfffff) {
+            sub_r(ARMRegisters::S0, base, OP2_IMM | (offset >> 12) | (10 << 8));
+            dtr_d(isLoad, srcDst, ARMRegisters::S0, (offset & 0xfff) | transferFlag);
+        } else {
+            moveImm(offset, ARMRegisters::S0);
+            dtr_dr(isLoad, srcDst, base, ARMRegisters::S0 | transferFlag);
+        }
+    }
+}
+
+void ARMAssembler::baseIndexTransfer32(bool isLoad, RegisterID srcDst, RegisterID base, RegisterID index, int scale, int32_t offset)
+{
+    ARMWord op2;
+
+    ASSERT(scale >= 0 && scale <= 3);
+    op2 = lsl(index, scale);
+
+    if (offset >= 0 && offset <= 0xfff) {
+        add_r(ARMRegisters::S0, base, op2);
+        dtr_u(isLoad, srcDst, ARMRegisters::S0, offset);
+        return;
+    }
+    if (offset <= 0 && offset >= -0xfff) {
+        add_r(ARMRegisters::S0, base, op2);
+        dtr_d(isLoad, srcDst, ARMRegisters::S0, -offset);
+        return;
+    }
+
+    ldr_un_imm(ARMRegisters::S0, offset);
+    add_r(ARMRegisters::S0, ARMRegisters::S0, op2);
+    dtr_ur(isLoad, srcDst, base, ARMRegisters::S0);
+}
+
+void ARMAssembler::doubleTransfer(bool isLoad, FPRegisterID srcDst, RegisterID base, int32_t offset)
+{
+    if (offset & 0x3) {
+        if (offset <= 0x3ff && offset >= 0) {
+            fdtr_u(isLoad, srcDst, base, offset >> 2);
+            return;
+        }
+        if (offset <= 0x3ffff && offset >= 0) {
+            add_r(ARMRegisters::S0, base, OP2_IMM | (offset >> 10) | (11 << 8));
+            fdtr_u(isLoad, srcDst, ARMRegisters::S0, (offset >> 2) & 0xff);
+            return;
+        }
+        offset = -offset;
+
+        if (offset <= 0x3ff && offset >= 0) {
+            fdtr_d(isLoad, srcDst, base, offset >> 2);
+            return;
+        }
+        if (offset <= 0x3ffff && offset >= 0) {
+            sub_r(ARMRegisters::S0, base, OP2_IMM | (offset >> 10) | (11 << 8));
+            fdtr_d(isLoad, srcDst, ARMRegisters::S0, (offset >> 2) & 0xff);
+            return;
+        }
+        offset = -offset;
+    }
+
+    ldr_un_imm(ARMRegisters::S0, offset);
+    add_r(ARMRegisters::S0, ARMRegisters::S0, base);
+    fdtr_u(isLoad, srcDst, ARMRegisters::S0, 0);
+}
+
+void* ARMAssembler::executableCopy(ExecutablePool* allocator)
+{
+    // 64-bit alignment is required for next constant pool and JIT code as well
+    m_buffer.flushWithoutBarrier(true);
+    if (m_buffer.uncheckedSize() & 0x7)
+        bkpt(0);
+
+    char* data = reinterpret_cast<char*>(m_buffer.executableCopy(allocator));
+
+    for (Jumps::Iterator iter = m_jumps.begin(); iter != m_jumps.end(); ++iter) {
+        // The last bit is set if the constant must be placed on constant pool.
+        int pos = (*iter) & (~0x1);
+        ARMWord* ldrAddr = reinterpret_cast<ARMWord*>(data + pos);
+        ARMWord* addr = getLdrImmAddress(ldrAddr);
+        if (*addr != InvalidBranchTarget) {
+            if (!(*iter & 1)) {
+                int diff = reinterpret_cast<ARMWord*>(data + *addr) - (ldrAddr + DefaultPrefetching);
+
+                if ((diff <= BOFFSET_MAX && diff >= BOFFSET_MIN)) {
+                    *ldrAddr = B | getConditionalField(*ldrAddr) | (diff & BRANCH_MASK);
+                    continue;
+                }
+            }
+            *addr = reinterpret_cast<ARMWord>(data + *addr);
+        }
+    }
+
+    return data;
+}
+
+} // namespace JSC
+
+#endif // ENABLE(ASSEMBLER) && CPU(ARM_TRADITIONAL)