Revert r12646 "Support for SDIV" because of failing V8 benchmark.

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index 1216486e68993d68cc5aa49085b37df778e69d34..e07118317c464ba1041fc36814dfcfda6b56fb16 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -979,132 +979,109 @@ void LCodeGen::DoModI(LModI* instr) {
   Register left = ToRegister(instr->left());
   Register right = ToRegister(instr->right());
   Register result = ToRegister(instr->result());
-  Label done;
 
-  if (CpuFeatures::IsSupported(SUDIV)) {
-    CpuFeatures::Scope scope(SUDIV);
-    // Check for x % 0.
-    if (instr->hydrogen()->CheckFlag(HValue::kCanBeDivByZero)) {
-      __ cmp(right, Operand(0));
-      DeoptimizeIf(eq, instr->environment());
-    }
+  Register scratch = scratch0();
+  Register scratch2 = ToRegister(instr->temp());
+  DwVfpRegister dividend = ToDoubleRegister(instr->temp2());
+  DwVfpRegister divisor = ToDoubleRegister(instr->temp3());
+  DwVfpRegister quotient = double_scratch0();
 
-    // For  r3 = r1 % r2; we can have the following ARM code
-    // sdiv r3, r1, r2
-    // mls r3, r3, r2, r1
+  ASSERT(!dividend.is(divisor));
+  ASSERT(!dividend.is(quotient));
+  ASSERT(!divisor.is(quotient));
+  ASSERT(!scratch.is(left));
+  ASSERT(!scratch.is(right));
+  ASSERT(!scratch.is(result));
 
-    __ sdiv(result, left, right);
-    __ mls(result, result, right, left);
-    __ cmp(result, Operand(0));
-    __ b(ne, &done);
+  Label done, vfp_modulo, both_positive, right_negative;
 
-    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
-       __ cmp(left, Operand(0));
-       DeoptimizeIf(lt, instr->environment());
-    }
-  } else {
-    Register scratch = scratch0();
-    Register scratch2 = ToRegister(instr->temp());
-    DwVfpRegister dividend = ToDoubleRegister(instr->temp2());
-    DwVfpRegister divisor = ToDoubleRegister(instr->temp3());
-    DwVfpRegister quotient = double_scratch0();
-
-    ASSERT(!dividend.is(divisor));
-    ASSERT(!dividend.is(quotient));
-    ASSERT(!divisor.is(quotient));
-    ASSERT(!scratch.is(left));
-    ASSERT(!scratch.is(right));
-    ASSERT(!scratch.is(result));
-
-    Label done, vfp_modulo, both_positive, right_negative;
-
-    // Check for x % 0.
-    if (instr->hydrogen()->CheckFlag(HValue::kCanBeDivByZero)) {
-      __ cmp(right, Operand(0));
-      DeoptimizeIf(eq, instr->environment());
-    }
-
-    __ Move(result, left);
-
-    // (0 % x) must yield 0 (if x is finite, which is the case here).
-    __ cmp(left, Operand(0));
-    __ b(eq, &done);
-    // Preload right in a vfp register.
-    __ vmov(divisor.low(), right);
-    __ b(lt, &vfp_modulo);
+  // Check for x % 0.
+  if (instr->hydrogen()->CheckFlag(HValue::kCanBeDivByZero)) {
+    __ cmp(right, Operand(0));
+    DeoptimizeIf(eq, instr->environment());
+  }
 
-    __ cmp(left, Operand(right));
-    __ b(lt, &done);
+  __ Move(result, left);
 
-    // Check for (positive) power of two on the right hand side.
-    __ JumpIfNotPowerOfTwoOrZeroAndNeg(right,
-                                       scratch,
-                                       &right_negative,
-                                       &both_positive);
-    // Perform modulo operation (scratch contains right - 1).
-    __ and_(result, scratch, Operand(left));
-    __ b(&done);
+  // (0 % x) must yield 0 (if x is finite, which is the case here).
+  __ cmp(left, Operand(0));
+  __ b(eq, &done);
+  // Preload right in a vfp register.
+  __ vmov(divisor.low(), right);
+  __ b(lt, &vfp_modulo);
 
-    __ bind(&right_negative);
-    // Negate right. The sign of the divisor does not matter.
-    __ rsb(right, right, Operand(0));
-
-    __ bind(&both_positive);
-    const int kUnfolds = 3;
-    // If the right hand side is smaller than the (nonnegative)
-    // left hand side, the left hand side is the result.
-    // Else try a few subtractions of the left hand side.
-    __ mov(scratch, left);
-    for (int i = 0; i < kUnfolds; i++) {
-      // Check if the left hand side is less or equal than the
-      // the right hand side.
-      __ cmp(scratch, Operand(right));
-      __ mov(result, scratch, LeaveCC, lt);
-      __ b(lt, &done);
-      // If not, reduce the left hand side by the right hand
-      // side and check again.
-      if (i < kUnfolds - 1) __ sub(scratch, scratch, right);
-    }
+  __ cmp(left, Operand(right));
+  __ b(lt, &done);
+
+  // Check for (positive) power of two on the right hand side.
+  __ JumpIfNotPowerOfTwoOrZeroAndNeg(right,
+                                     scratch,
+                                     &right_negative,
+                                     &both_positive);
+  // Perform modulo operation (scratch contains right - 1).
+  __ and_(result, scratch, Operand(left));
+  __ b(&done);
 
-    __ bind(&vfp_modulo);
-    // Load the arguments in VFP registers.
-    // The divisor value is preloaded before. Be careful that 'right'
-    // is only live on entry.
-    __ vmov(dividend.low(), left);
-    // From here on don't use right as it may have been reallocated
-    // (for example to scratch2).
-    right = no_reg;
-
-    __ vcvt_f64_s32(dividend, dividend.low());
-    __ vcvt_f64_s32(divisor, divisor.low());
-
-    // We do not care about the sign of the divisor.
-    __ vabs(divisor, divisor);
-    // Compute the quotient and round it to a 32bit integer.
-    __ vdiv(quotient, dividend, divisor);
-    __ vcvt_s32_f64(quotient.low(), quotient);
-    __ vcvt_f64_s32(quotient, quotient.low());
-
-    // Compute the remainder in result.
-    DwVfpRegister double_scratch = dividend;
-    __ vmul(double_scratch, divisor, quotient);
-    __ vcvt_s32_f64(double_scratch.low(), double_scratch);
-    __ vmov(scratch, double_scratch.low());
-
-    if (!instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
-      __ sub(result, left, scratch);
-    } else {
-      Label ok;
-      // Check for -0.
-      __ sub(scratch2, left, scratch, SetCC);
-      __ b(ne, &ok);
-      __ cmp(left, Operand(0));
-      DeoptimizeIf(mi, instr->environment());
-      __ bind(&ok);
-      // Load the result and we are done.
-      __ mov(result, scratch2);
-    }
+  __ bind(&right_negative);
+  // Negate right. The sign of the divisor does not matter.
+  __ rsb(right, right, Operand(0));
+
+  __ bind(&both_positive);
+  const int kUnfolds = 3;
+  // If the right hand side is smaller than the (nonnegative)
+  // left hand side, the left hand side is the result.
+  // Else try a few subtractions of the left hand side.
+  __ mov(scratch, left);
+  for (int i = 0; i < kUnfolds; i++) {
+    // Check if the left hand side is less or equal than the
+    // the right hand side.
+    __ cmp(scratch, Operand(right));
+    __ mov(result, scratch, LeaveCC, lt);
+    __ b(lt, &done);
+    // If not, reduce the left hand side by the right hand
+    // side and check again.
+    if (i < kUnfolds - 1) __ sub(scratch, scratch, right);
+  }
+
+  __ bind(&vfp_modulo);
+  // Load the arguments in VFP registers.
+  // The divisor value is preloaded before. Be careful that 'right' is only live
+  // on entry.
+  __ vmov(dividend.low(), left);
+  // From here on don't use right as it may have been reallocated (for example
+  // to scratch2).
+  right = no_reg;
+
+  __ vcvt_f64_s32(dividend, dividend.low());
+  __ vcvt_f64_s32(divisor, divisor.low());
+
+  // We do not care about the sign of the divisor.
+  __ vabs(divisor, divisor);
+  // Compute the quotient and round it to a 32bit integer.
+  __ vdiv(quotient, dividend, divisor);
+  __ vcvt_s32_f64(quotient.low(), quotient);
+  __ vcvt_f64_s32(quotient, quotient.low());
+
+  // Compute the remainder in result.
+  DwVfpRegister double_scratch = dividend;
+  __ vmul(double_scratch, divisor, quotient);
+  __ vcvt_s32_f64(double_scratch.low(), double_scratch);
+  __ vmov(scratch, double_scratch.low());
+
+  if (!instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
+    __ sub(result, left, scratch);
+  } else {
+    Label ok;
+    // Check for -0.
+    __ sub(scratch2, left, scratch, SetCC);
+    __ b(ne, &ok);
+    __ cmp(left, Operand(0));
+    DeoptimizeIf(mi, instr->environment());
+    __ bind(&ok);
+    // Load the result and we are done.
+    __ mov(result, scratch2);
   }
+
   __ bind(&done);
 }