[Turbofan] CodeGenerator for ARM avoids moves from VFP to general regs.

src/arm/macro-assembler-arm.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <limits.h>  // For LONG_MIN, LONG_MAX.
 
 #if V8_TARGET_ARCH_ARM
 
 #include "src/base/bits.h"
 #include "src/base/division-by-constant.h"
@@ skipping 1033 matching lines @@
 
 void MacroAssembler::VmovLow(DwVfpRegister dst, Register src) {
   if (dst.code() < 16) {
     const LowDwVfpRegister loc = LowDwVfpRegister::from_code(dst.code());
     vmov(loc.low(), src);
   } else {
     vmov(dst, VmovIndexLo, src);
   }
 }
 
-void MacroAssembler::VmovExtended(Register dst, int src_code) {
-  DCHECK_LE(32, src_code);
-  DCHECK_GT(64, src_code);
-  if (src_code & 0x1) {
-    VmovHigh(dst, DwVfpRegister::from_code(src_code / 2));
-  } else {
-    VmovLow(dst, DwVfpRegister::from_code(src_code / 2));
-  }
-}
-
-void MacroAssembler::VmovExtended(int dst_code, Register src) {
-  DCHECK_LE(32, dst_code);
-  DCHECK_GT(64, dst_code);
-  if (dst_code & 0x1) {
-    VmovHigh(DwVfpRegister::from_code(dst_code / 2), src);
-  } else {
-    VmovLow(DwVfpRegister::from_code(dst_code / 2), src);
-  }
-}
-
-void MacroAssembler::VmovExtended(int dst_code, int src_code,
-                                  Register scratch) {
+void MacroAssembler::VmovExtended(int dst_code, int src_code) {
   if (src_code < 32 && dst_code < 32) {
     // src and dst are both s-registers.
     vmov(SwVfpRegister::from_code(dst_code),
          SwVfpRegister::from_code(src_code));
   } else if (src_code < 32) {
-    // src is an s-register.
-    vmov(scratch, SwVfpRegister::from_code(src_code));
-    VmovExtended(dst_code, scratch);
+    // src is s-register, dst is in high d-register. Move dst into scratch
+    // d-register to do the s-register move, then back.
+    DCHECK_GT(64, dst_code);
+    DwVfpRegister dst_reg = DwVfpRegister::from_code(dst_code / 2);
+    int dst_s_code = kScratchDoubleReg.low().code() + (dst_code & 1);
+    vmov(kScratchDoubleReg, dst_reg);
+    vmov(SwVfpRegister::from_code(dst_s_code),
+         SwVfpRegister::from_code(src_code));
+    vmov(dst_reg, kScratchDoubleReg);
   } else if (dst_code < 32) {
-    // dst is an s-register.
-    VmovExtended(scratch, src_code);
-    vmov(SwVfpRegister::from_code(dst_code), scratch);
+    // src is in high d-register, dst is an s-register. Move src into scratch
+    // d-register, do the s-register move.
+    DCHECK_GT(64, src_code);
+    DwVfpRegister src_reg = DwVfpRegister::from_code(src_code / 2);
+    int src_s_code = kScratchDoubleReg.low().code() + (src_code & 1);
+    vmov(kScratchDoubleReg, src_reg);
+    vmov(SwVfpRegister::from_code(dst_code),
+         SwVfpRegister::from_code(src_s_code));
   } else {
-    // Neither src or dst are s-registers.
+    // src and dst are in high d-registers. Move both into free registers,
+    // do the s-register move, then move dst back.
     DCHECK_GT(64, src_code);
     DCHECK_GT(64, dst_code);
-    VmovExtended(scratch, src_code);
-    VmovExtended(dst_code, scratch);
+    DwVfpRegister dst_reg = DwVfpRegister::from_code(dst_code / 2);
+    DwVfpRegister src_reg = DwVfpRegister::from_code(src_code / 2);
+    int dst_s_code = kScratchDoubleReg.low().code() + (dst_code & 1);
+    int src_s_code = kDoubleRegZero.low().code() + (src_code & 1);
+    vmov(kScratchDoubleReg, dst_reg);
+    vmov(kDoubleRegZero, src_reg);
+    vmov(SwVfpRegister::from_code(dst_s_code),
+         SwVfpRegister::from_code(src_s_code));
+    vmov(dst_reg, kScratchDoubleReg);
+    vmov(kDoubleRegZero, 0.0);  // restore zero register
   }
 }
 
-void MacroAssembler::VmovExtended(int dst_code, const MemOperand& src,
-                                  Register scratch) {
-  if (dst_code >= 32) {
-    ldr(scratch, src);
-    VmovExtended(dst_code, scratch);
+void MacroAssembler::VmovExtended(int dst_code, const MemOperand& src) {
+  if (dst_code < 32) {
+    vldr(SwVfpRegister::from_code(dst_code), src);
   } else {
-    vldr(SwVfpRegister::from_code(dst_code), src);
+    // dst is in high d-register, move it down, load src, then move it back up.
+    DCHECK_GT(64, dst_code);
+    DwVfpRegister dst_reg = DwVfpRegister::from_code(dst_code / 2);
+    int dst_s_code = kScratchDoubleReg.low().code() + (dst_code & 1);
+    vmov(kScratchDoubleReg, dst_reg);
+    vldr(SwVfpRegister::from_code(dst_s_code), src);
+    vmov(dst_reg, kScratchDoubleReg);
+  }
+}
+void MacroAssembler::VmovExtended(const MemOperand& dst, int src_code) {
+  if (src_code < 32) {
+    vstr(SwVfpRegister::from_code(src_code), dst);
+  } else {
+    // src is in high d-register, move it down, store src.
+    DCHECK_GT(64, src_code);
+    DwVfpRegister src_reg = DwVfpRegister::from_code(src_code / 2);
+    int src_s_code = kScratchDoubleReg.low().code() + (src_code & 1);
+    vmov(kScratchDoubleReg, src_reg);
+    vstr(SwVfpRegister::from_code(src_s_code), dst);
   }
 }
 
-void MacroAssembler::VmovExtended(const MemOperand& dst, int src_code,
-                                  Register scratch) {
-  if (src_code >= 32) {
-    VmovExtended(scratch, src_code);
-    str(scratch, dst);
+void MacroAssembler::VswpExtended(int dst_code, int src_code) {
+  if (src_code < 32 && dst_code < 32) {
+    // src and dst are both s-registers.
+    vmov(kScratchDoubleReg.low(), SwVfpRegister::from_code(dst_code));
+    vmov(SwVfpRegister::from_code(dst_code),
+         SwVfpRegister::from_code(src_code));
+    vmov(SwVfpRegister::from_code(src_code), kScratchDoubleReg.low());
+  } else if (src_code < 32) {
+    // src is s-register, dst is in high d-register. Move dst into scratch
+    // d-register to do the s-register swap, then back.
+    DCHECK_GT(64, dst_code);
+    DwVfpRegister dst_reg = DwVfpRegister::from_code(dst_code / 2);
+    int dst_s_code = kScratchDoubleReg.low().code() + (dst_code & 1);
+    int dst_s_temp = kDoubleRegZero.low().code() + (dst_code & 1);
+    vmov(kScratchDoubleReg, dst_reg);
+    vmov(kDoubleRegZero, dst_reg);
+    vmov(SwVfpRegister::from_code(dst_s_code),
+         SwVfpRegister::from_code(src_code));
+    vmov(dst_reg, kScratchDoubleReg);
+    vmov(SwVfpRegister::from_code(src_code),
+         SwVfpRegister::from_code(dst_s_temp));
+    vmov(kDoubleRegZero, 0.0);  // restore zero register
+  } else if (dst_code < 32) {
+    // src is in high d-register, dst is an s-register. Move src into scratch
+    // d-register, do the s-register swap.
+    DCHECK_GT(64, src_code);
+    DwVfpRegister src_reg = DwVfpRegister::from_code(src_code / 2);
+    int src_s_code = kScratchDoubleReg.low().code() + (src_code & 1);
+    int src_s_temp = kDoubleRegZero.low().code() + (src_code & 1);
+    vmov(kScratchDoubleReg, src_reg);
+    vmov(kDoubleRegZero, src_reg);
+    vmov(SwVfpRegister::from_code(src_s_code),
+         SwVfpRegister::from_code(dst_code));
+    vmov(src_reg, kScratchDoubleReg);
+    vmov(SwVfpRegister::from_code(dst_code),
+         SwVfpRegister::from_code(src_s_temp));
+    vmov(kDoubleRegZero, 0.0);  // restore zero register
   } else {
-    vstr(SwVfpRegister::from_code(src_code), dst);
+    // src and dst are in high d-registers. Move both into free registers,
+    // do the s-register swap, then move both back.
+    DCHECK_GT(64, src_code);
+    DCHECK_GT(64, dst_code);
+    DwVfpRegister dst_reg = DwVfpRegister::from_code(dst_code / 2);
+    DwVfpRegister src_reg = DwVfpRegister::from_code(src_code / 2);
+    int dst_s_code = kScratchDoubleReg.low().code() + (dst_code & 1);
+    int src_s_code = kDoubleRegZero.low().code() + (src_code & 1);
+    vmov(kScratchDoubleReg, dst_reg);
+    vmov(kDoubleRegZero, src_reg);
+    vmov(SwVfpRegister::from_code(src_s_code ^ 1),
+         SwVfpRegister::from_code(dst_s_code));
+    vmov(SwVfpRegister::from_code(dst_s_code),
+         SwVfpRegister::from_code(src_s_code));
+    vmov(dst_reg, kScratchDoubleReg);
+    vmov(kScratchDoubleReg, src_reg);
+    vmov(SwVfpRegister::from_code(dst_s_code),
+         SwVfpRegister::from_code(src_s_code ^ 1));
+    vmov(src_reg, kScratchDoubleReg);
+    vmov(kDoubleRegZero, 0.0);  // restore zero register
   }
 }
 
+void MacroAssembler::VswpExtended(const MemOperand& dst, int src_code) {
+  if (src_code < 32) {
+    vldr(kScratchDoubleReg.low(), dst);
+    vstr(SwVfpRegister::from_code(src_code), dst);
+    vmov(SwVfpRegister::from_code(src_code), kScratchDoubleReg.low());
+  } else {
+    // src is in high d-register, move it down, do the swap, move src back up.
+    DCHECK_GT(64, src_code);
+    DwVfpRegister src_reg = DwVfpRegister::from_code(src_code / 2);
+    int src_s_code = kScratchDoubleReg.low().code() + (src_code & 1);
+    vmov(kScratchDoubleReg, src_reg);
+    vldr(kDoubleRegZero.low(), dst);
+    vstr(SwVfpRegister::from_code(src_s_code), dst);
+    vmov(SwVfpRegister::from_code(src_s_code), kDoubleRegZero.low());
+    vmov(src_reg, kScratchDoubleReg);
+    vmov(kDoubleRegZero, 0.0);  // restore zero register
+  }
+}
+
 void MacroAssembler::LslPair(Register dst_low, Register dst_high,
                              Register src_low, Register src_high,
                              Register scratch, Register shift) {
   DCHECK(!AreAliased(dst_high, src_low));
   DCHECK(!AreAliased(dst_high, shift));
 
   Label less_than_32;
   Label done;
   rsb(scratch, shift, Operand(32), SetCC);
   b(gt, &less_than_32);
@@ skipping 2867 matching lines @@
     }
   }
   if (mag.shift > 0) mov(result, Operand(result, ASR, mag.shift));
   add(result, result, Operand(dividend, LSR, 31));
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM