MIPS: Support r6 max, min floating point instructions.

src/mips64/macro-assembler-mips64.cc

Index: src/mips64/macro-assembler-mips64.cc
diff --git a/src/mips64/macro-assembler-mips64.cc b/src/mips64/macro-assembler-mips64.cc
index 701420bfd653869cd172ad680538d9012411ba1a..3c068ad0dac0f630ad0a5efac3e864376919b0a6 100644
--- a/src/mips64/macro-assembler-mips64.cc
+++ b/src/mips64/macro-assembler-mips64.cc
@@ -2362,6 +2362,186 @@ void MacroAssembler::Movf(Register rd, Register rs, uint16_t cc) {
   movf(rd, rs, cc);
 }
 
+#define __ masm->
+
+static bool ZeroHelper_d(MacroAssembler* masm, MaxMinKind kind, FPURegister dst,
+                         FPURegister src1, FPURegister src2, Label* equal) {
+  if (src1.is(src2)) {
+    __ Move(dst, src1);
+    return true;
+  }
+
+  Label other, compare_not_equal;
+  FPURegister left, right;
+  if (kind == MaxMinKind::kMin) {
+    left = src1;
+    right = src2;
+  } else {
+    left = src2;
+    right = src1;
+  }
+
+  __ BranchF64(&compare_not_equal, nullptr, ne, src1, src2);
+  // Left and right hand side are equal, check for -0 vs. +0.
+  __ dmfc1(t8, src1);
+  __ Branch(&other, eq, t8, Operand(0x8000000000000000));
+  __ Move_d(dst, right);
+  __ Branch(equal);
+  __ bind(&other);
+  __ Move_d(dst, left);
+  __ Branch(equal);
+  __ bind(&compare_not_equal);
+  return false;
+}
+
+static bool ZeroHelper_s(MacroAssembler* masm, MaxMinKind kind, FPURegister dst,
+                         FPURegister src1, FPURegister src2, Label* equal) {
+  if (src1.is(src2)) {
+    __ Move(dst, src1);
+    return true;
+  }
+
+  Label other, compare_not_equal;
+  FPURegister left, right;
+  if (kind == MaxMinKind::kMin) {
+    left = src1;
+    right = src2;
+  } else {
+    left = src2;
+    right = src1;
+  }
+
+  __ BranchF32(&compare_not_equal, nullptr, ne, src1, src2);
+  // Left and right hand side are equal, check for -0 vs. +0.
+  __ FmoveLow(t8, src1);
+  __ dsll32(t8, t8, 0);
+  __ Branch(&other, eq, t8, Operand(0x8000000000000000));
+  __ Move_s(dst, right);
+  __ Branch(equal);
+  __ bind(&other);
+  __ Move_s(dst, left);
+  __ Branch(equal);
+  __ bind(&compare_not_equal);
+  return false;
+}
+
+#undef __
+
+void MacroAssembler::MinNaNCheck_d(FPURegister dst, FPURegister src1,
+                                   FPURegister src2, Label* nan) {
+  if (nan) {
+    BranchF64(nullptr, nan, eq, src1, src2);
+  }
+  if (kArchVariant >= kMips64r6) {
+    min_d(dst, src1, src2);
+  } else {
+    Label skip;
+    if (!ZeroHelper_d(this, MaxMinKind::kMin, dst, src1, src2, &skip)) {
+      if (dst.is(src1)) {
+        BranchF64(&skip, nullptr, le, src1, src2);
+        Move_d(dst, src2);
+      } else if (dst.is(src2)) {
+        BranchF64(&skip, nullptr, ge, src1, src2);
+        Move_d(dst, src1);
+      } else {
+        Label right;
+        BranchF64(&right, nullptr, gt, src1, src2);
+        Move_d(dst, src1);
+        Branch(&skip);
+        bind(&right);
+        Move_d(dst, src2);
+      }
+    }
+    bind(&skip);
+  }
+}
+
+void MacroAssembler::MaxNaNCheck_d(FPURegister dst, FPURegister src1,
+                                   FPURegister src2, Label* nan) {
+  if (nan) {
+    BranchF64(nullptr, nan, eq, src1, src2);
+  }
+  if (kArchVariant >= kMips64r6) {
+    max_d(dst, src1, src2);
+  } else {
+    Label skip;
+    if (!ZeroHelper_d(this, MaxMinKind::kMax, dst, src1, src2, &skip)) {
+      if (dst.is(src1)) {
+        BranchF64(&skip, nullptr, ge, src1, src2);
+        Move_d(dst, src2);
+      } else if (dst.is(src2)) {
+        BranchF64(&skip, nullptr, le, src1, src2);
+        Move_d(dst, src1);
+      } else {
+        Label right;
+        BranchF64(&right, nullptr, lt, src1, src2);
+        Move_d(dst, src1);
+        Branch(&skip);
+        bind(&right);
+        Move_d(dst, src2);
+      }
+    }
+    bind(&skip);
+  }
+}
+
+void MacroAssembler::MinNaNCheck_s(FPURegister dst, FPURegister src1,
+                                   FPURegister src2, Label* nan) {
+  if (nan) {
+    BranchF32(nullptr, nan, eq, src1, src2);
+  }
+  if (kArchVariant >= kMips64r6) {
+    min_s(dst, src1, src2);
+  } else {
+    Label skip;
+    if (!ZeroHelper_s(this, MaxMinKind::kMin, dst, src1, src2, &skip)) {
+      if (dst.is(src1)) {
+        BranchF32(&skip, nullptr, le, src1, src2);
+        Move_s(dst, src2);
+      } else if (dst.is(src2)) {
+        BranchF32(&skip, nullptr, ge, src1, src2);
+        Move_s(dst, src1);
+      } else {
+        Label right;
+        BranchF32(&right, nullptr, gt, src1, src2);
+        Move_s(dst, src1);
+        Branch(&skip);
+        bind(&right);
+        Move_s(dst, src2);
+      }
+    }
+    bind(&skip);
+  }
+}
+
+void MacroAssembler::MaxNaNCheck_s(FPURegister dst, FPURegister src1,
+                                   FPURegister src2, Label* nan) {
+  if (nan) {
+    BranchF32(nullptr, nan, eq, src1, src2);
+  }
+  if (kArchVariant >= kMips64r6) {
+    max_s(dst, src1, src2);
+  } else {
+    Label skip;
+    if (!ZeroHelper_s(this, MaxMinKind::kMax, dst, src1, src2, &skip)) {
+      if (dst.is(src1)) {
+        BranchF32(&skip, nullptr, ge, src1, src2);
+        Move_s(dst, src2);
+      } else if (dst.is(src2)) {
+        BranchF32(&skip, nullptr, le, src1, src2);
+        Move_s(dst, src1);
+      } else {
+        Label right;
+        BranchF32(&right, nullptr, lt, src1, src2);
+        Move_s(dst, src1);
+        Branch(&skip);
+        bind(&right);
+        Move_s(dst, src2);
+      }
+    }
+    bind(&skip);
+  }
+}
 
 void MacroAssembler::Clz(Register rd, Register rs) {
   clz(rd, rs);