From dbce0d738e9d7956d2bd73e932a0fdd28f2229b4 Mon Sep 17 00:00:00 2001
From: Chris Larsen <chris.larsen@imgtec.com>
Date: Thu, 17 Sep 2015 13:34:00 -0700
Subject: MIPS64r6 Assembler Tests

Assembler tests for:

- SQRT.fmt    - ABS.fmt     - ROUND.L.fmt - ROUND.W.fmt
- CEIL.L.fmt  - CEIL.W.fmt  - FLOOR.L.fmt - FLOOR.W.fmt
- SEL.fmt     - RINT.fmt    - CLASS.fmt   - MIN.fmt
- MAX.fmt     - cvt.d.l     - BITSWAP     - DBITSWAP
- DSBH        - DSHD        - WSBH        - ROTR
- SELEQZ      - SELNEZ      - CLZ         - CLO
- DCLZ        - DCLO        - SC          - SCD
- LL          - LLD

These are the assembler instructions which were added to support
intrinsic functions on MIPS64. Tests for additional assembler
instructions will follow.

Support added to the testing infrastructure for:

- Assembler instructions which use three registers; previously
  instructions were limited to one, or two, registers.
- Immediate values which have their sizes specified by the number of
  bits required to store them rather than the number of bytes, in both
  signed and unsigned versions.

Change-Id: I38c07dcbf2539825b25bed13aac05a26fa594b0b
---
 runtime/base/bit_utils.h | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

(limited to 'runtime/base/bit_utils.h')

diff --git a/runtime/base/bit_utils.h b/runtime/base/bit_utils.h
index 1b0d774419..9c78ee59dd 100644
--- a/runtime/base/bit_utils.h
+++ b/runtime/base/bit_utils.h
@@ -263,6 +263,33 @@ static constexpr bool IsAbsoluteUint(T value) {
                       : static_cast<unsigned_type>(value));
 }
 
+// Generate maximum/minimum values for signed/unsigned n-bit integers
+template <typename T>
+static constexpr T MaxInt(size_t bits) {
+  return
+      DCHECK_CONSTEXPR(bits > 0, "bits cannot be zero", 0)
+      DCHECK_CONSTEXPR(bits <= BitSizeOf<T>(), "kBits must be < max.", 0)
+      bits == BitSizeOf<T>()
+          ? std::numeric_limits<T>::max()
+          : std::is_signed<T>::value
+                ? (bits == 1
+                       ? 0
+                       : static_cast<T>(MaxInt<typename std::make_unsigned<T>::type>(bits - 1)))
+                : static_cast<T>(UINT64_C(1) << bits) - static_cast<T>(1);
+}
+
+template <typename T>
+static constexpr T MinInt(size_t bits) {
+  return
+      DCHECK_CONSTEXPR(bits > 0, "bits cannot be zero", 0)
+      DCHECK_CONSTEXPR(bits <= BitSizeOf<T>(), "kBits must be < max.", 0)
+      bits == BitSizeOf<T>()
+          ? std::numeric_limits<T>::min()
+          : std::is_signed<T>::value
+                ? (bits == 1 ? -1 : static_cast<T>(-1) - MaxInt<T>(bits))
+                : static_cast<T>(0);
+}
+
 // Using the Curiously Recurring Template Pattern to implement everything shared
 // by LowToHighBitIterator and HighToLowBitIterator, i.e. everything but operator*().
 template <typename T, typename Iter>
-- 
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