Bug 1464366 : [MIPS] Provide implementation for CodeGenerator::visitTrunc{F}; r=jandem

--HG--
extra : rebase_source : 11facc1f91e4a3155be8067e2293ff6001ee41b7

js/src/jit/mips-shared/CodeGenerator-mips-shared.cpp

@@ -1455,13 +1455,43 @@ CodeGenerator::visitRoundF(LRoundF* lir)
 void
 CodeGenerator::visitTrunc(LTrunc* lir)
 {
-    MOZ_CRASH("visitTrunc");
+    FloatRegister input = ToFloatRegister(lir->input());
+    Register output = ToRegister(lir->output());
+
+    Label notZero;
+    masm.as_truncwd(ScratchFloat32Reg, input);
+    masm.as_cfc1(ScratchRegister, Assembler::FCSR);
+    masm.moveFromFloat32(ScratchFloat32Reg, output);
+    masm.ma_ext(ScratchRegister, ScratchRegister, Assembler::CauseV, 1);
+
+    masm.ma_b(output, Imm32(0), &notZero, Assembler::NotEqual, ShortJump);
+    masm.moveFromDoubleHi(input, ScratchRegister);
+    // Check if input is in ]-1; -0] range by checking the sign bit.
+    masm.as_slt(ScratchRegister, ScratchRegister, zero);
+    masm.bind(&notZero);
+
+    bailoutCmp32(Assembler::NotEqual, ScratchRegister, Imm32(0), lir->snapshot());
 }
 
 void
 CodeGenerator::visitTruncF(LTruncF* lir)
 {
-    MOZ_CRASH("visitTruncF");
+    FloatRegister input = ToFloatRegister(lir->input());
+    Register output = ToRegister(lir->output());
+
+    Label notZero;
+    masm.as_truncws(ScratchFloat32Reg, input);
+    masm.as_cfc1(ScratchRegister, Assembler::FCSR);
+    masm.moveFromFloat32(ScratchFloat32Reg, output);
+    masm.ma_ext(ScratchRegister, ScratchRegister, Assembler::CauseV, 1);
+
+    masm.ma_b(output, Imm32(0), &notZero, Assembler::NotEqual, ShortJump);
+    masm.moveFromFloat32(input, ScratchRegister);
+    // Check if input is in ]-1; -0] range by checking the sign bit.
+    masm.as_slt(ScratchRegister, ScratchRegister, zero);
+    masm.bind(&notZero);
+
+    bailoutCmp32(Assembler::NotEqual, ScratchRegister, Imm32(0), lir->snapshot());
 }
 
 void