Mesa (master): aco: allow 64-bit literals if they can be sign/zero-extended from 32-bit

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Module: Mesa
Branch: master
Commit: b10de4c1d8fc495b042632d8122b957d5ca09af0
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=b10de4c1d8fc495b042632d8122b957d5ca09af0

Author: Rhys Perry <pendingchaos02 at gmail.com>
Date:   Mon Nov 30 14:46:54 2020 +0000

aco: allow 64-bit literals if they can be sign/zero-extended from 32-bit

Signed-off-by: Rhys Perry <pendingchaos02 at gmail.com>
Reviewed-by: Daniel Schürmann <daniel at schuermann.dev>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7798>

---

 src/amd/compiler/aco_ir.h | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/amd/compiler/aco_ir.h b/src/amd/compiler/aco_ir.h
index d6e936c6caa..0b313ca0dfb 100644
--- a/src/amd/compiler/aco_ir.h
+++ b/src/amd/compiler/aco_ir.h
@@ -421,7 +421,7 @@ public:
    constexpr Operand()
       : reg_(PhysReg{128}), isTemp_(false), isFixed_(true), isConstant_(false),
         isKill_(false), isUndef_(true), isFirstKill_(false), constSize(0),
-        isLateKill_(false), is16bit_(false), is24bit_(false) {}
+        isLateKill_(false), is16bit_(false), is24bit_(false), signext(false) {}
 
    explicit Operand(Temp r) noexcept
    {
@@ -538,8 +538,10 @@ public:
          data_.i = 0xc0800000;
          setFixed(PhysReg{247});
       } else { /* Literal Constant: we don't know if it is a long or double.*/
-         isConstant_ = 0;
-         assert(false && "attempt to create a 64-bit literal constant");
+         signext = v >> 63;
+         data_.i = v & 0xffffffffu;
+         setFixed(PhysReg{255});
+         assert(constantValue64() == v && "attempt to create a unrepresentable 64-bit literal constant");
       }
    };
    explicit Operand(RegClass type) noexcept
@@ -667,6 +669,8 @@ public:
             return 0x4010000000000000;
          case 247:
             return 0xC010000000000000;
+         case 255:
+            return (signext && (data_.i & 0x80000000u) ? 0xffffffff00000000ull : 0ull) | data_.i;
          }
          unreachable("invalid register for 64-bit constant");
       } else {
@@ -785,6 +789,7 @@ private:
          uint8_t isLateKill_:1;
          uint8_t is16bit_:1;
          uint8_t is24bit_:1;
+         uint8_t signext:1;
       };
       /* can't initialize bit-fields in c++11, so work around using a union */
       uint16_t control_ = 0;