Add MIPS support to pixelflinger.

See the comment-block at the top of MIPSAssembler.cpp for
implementation overview.

Change-Id: Id492c10610574af8c89c38d19e12fafc3652c28a
diff --git a/libpixelflinger/codeflinger/ARMAssembler.cpp b/libpixelflinger/codeflinger/ARMAssembler.cpp
index 0dc5037..c4f42f5 100644
--- a/libpixelflinger/codeflinger/ARMAssembler.cpp
+++ b/libpixelflinger/codeflinger/ARMAssembler.cpp
@@ -76,6 +76,11 @@
     mComments.clear();
 }
 
+int ARMAssembler::getCodegenArch()
+{
+    return CODEGEN_ARCH_ARM;
+}
+
 // ----------------------------------------------------------------------------
 
 void ARMAssembler::disassemble(const char* name)
@@ -444,5 +449,146 @@
     *mPC++ = (cc<<28) | 0x7E00000 | ((width-1)<<16) | (Rd<<12) | (lsb<<7) | 0x50 | Rn;
 }
 
+#if 0
+#pragma mark -
+#pragma mark Addressing modes...
+#endif
+
+int ARMAssembler::buildImmediate(
+        uint32_t immediate, uint32_t& rot, uint32_t& imm)
+{
+    rot = 0;
+    imm = immediate;
+    if (imm > 0x7F) { // skip the easy cases
+        while (!(imm&3)  || (imm&0xFC000000)) {
+            uint32_t newval;
+            newval = imm >> 2;
+            newval |= (imm&3) << 30;
+            imm = newval;
+            rot += 2;
+            if (rot == 32) {
+                rot = 0;
+                break;
+            }
+        }
+    }
+    rot = (16 - (rot>>1)) & 0xF;
+
+    if (imm>=0x100)
+        return -EINVAL;
+
+    if (((imm>>(rot<<1)) | (imm<<(32-(rot<<1)))) != immediate)
+        return -1;
+
+    return 0;
+}
+
+// shifters...
+
+bool ARMAssembler::isValidImmediate(uint32_t immediate)
+{
+    uint32_t rot, imm;
+    return buildImmediate(immediate, rot, imm) == 0;
+}
+
+uint32_t ARMAssembler::imm(uint32_t immediate)
+{
+    uint32_t rot, imm;
+    int err = buildImmediate(immediate, rot, imm);
+
+    LOG_ALWAYS_FATAL_IF(err==-EINVAL,
+                        "immediate %08x cannot be encoded",
+                        immediate);
+
+    LOG_ALWAYS_FATAL_IF(err,
+                        "immediate (%08x) encoding bogus!",
+                        immediate);
+
+    return (1<<25) | (rot<<8) | imm;
+}
+
+uint32_t ARMAssembler::reg_imm(int Rm, int type, uint32_t shift)
+{
+    return ((shift&0x1F)<<7) | ((type&0x3)<<5) | (Rm&0xF);
+}
+
+uint32_t ARMAssembler::reg_rrx(int Rm)
+{
+    return (ROR<<5) | (Rm&0xF);
+}
+
+uint32_t ARMAssembler::reg_reg(int Rm, int type, int Rs)
+{
+    return ((Rs&0xF)<<8) | ((type&0x3)<<5) | (1<<4) | (Rm&0xF);
+}
+
+// addressing modes...
+// LDR(B)/STR(B)/PLD (immediate and Rm can be negative, which indicate U=0)
+uint32_t ARMAssembler::immed12_pre(int32_t immed12, int W)
+{
+    LOG_ALWAYS_FATAL_IF(abs(immed12) >= 0x800,
+                        "LDR(B)/STR(B)/PLD immediate too big (%08x)",
+                        immed12);
+    return (1<<24) | (((uint32_t(immed12)>>31)^1)<<23) |
+            ((W&1)<<21) | (abs(immed12)&0x7FF);
+}
+
+uint32_t ARMAssembler::immed12_post(int32_t immed12)
+{
+    LOG_ALWAYS_FATAL_IF(abs(immed12) >= 0x800,
+                        "LDR(B)/STR(B)/PLD immediate too big (%08x)",
+                        immed12);
+
+    return (((uint32_t(immed12)>>31)^1)<<23) | (abs(immed12)&0x7FF);
+}
+
+uint32_t ARMAssembler::reg_scale_pre(int Rm, int type,
+        uint32_t shift, int W)
+{
+    return  (1<<25) | (1<<24) |
+            (((uint32_t(Rm)>>31)^1)<<23) | ((W&1)<<21) |
+            reg_imm(abs(Rm), type, shift);
+}
+
+uint32_t ARMAssembler::reg_scale_post(int Rm, int type, uint32_t shift)
+{
+    return (1<<25) | (((uint32_t(Rm)>>31)^1)<<23) | reg_imm(abs(Rm), type, shift);
+}
+
+// LDRH/LDRSB/LDRSH/STRH (immediate and Rm can be negative, which indicate U=0)
+uint32_t ARMAssembler::immed8_pre(int32_t immed8, int W)
+{
+    uint32_t offset = abs(immed8);
+
+    LOG_ALWAYS_FATAL_IF(abs(immed8) >= 0x100,
+                        "LDRH/LDRSB/LDRSH/STRH immediate too big (%08x)",
+                        immed8);
+
+    return  (1<<24) | (1<<22) | (((uint32_t(immed8)>>31)^1)<<23) |
+            ((W&1)<<21) | (((offset&0xF0)<<4)|(offset&0xF));
+}
+
+uint32_t ARMAssembler::immed8_post(int32_t immed8)
+{
+    uint32_t offset = abs(immed8);
+
+    LOG_ALWAYS_FATAL_IF(abs(immed8) >= 0x100,
+                        "LDRH/LDRSB/LDRSH/STRH immediate too big (%08x)",
+                        immed8);
+
+    return (1<<22) | (((uint32_t(immed8)>>31)^1)<<23) |
+            (((offset&0xF0)<<4) | (offset&0xF));
+}
+
+uint32_t ARMAssembler::reg_pre(int Rm, int W)
+{
+    return (1<<24) | (((uint32_t(Rm)>>31)^1)<<23) | ((W&1)<<21) | (abs(Rm)&0xF);
+}
+
+uint32_t ARMAssembler::reg_post(int Rm)
+{
+    return (((uint32_t(Rm)>>31)^1)<<23) | (abs(Rm)&0xF);
+}
+
 }; // namespace android