From 2e1a84add57efd9f8a50a88d0569a48ae4b6d834 Mon Sep 17 00:00:00 2001
From: Yong He <yonghe@outlook.com>
Date: Fri, 18 Mar 2022 09:35:23 -0700
Subject: Fix type truncation during SCCP. (#2163)

---
 source/slang/slang-ir.cpp | 42 ++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 40 insertions(+), 2 deletions(-)

(limited to 'source/slang/slang-ir.cpp')

diff --git a/source/slang/slang-ir.cpp b/source/slang/slang-ir.cpp
index 721488f82..bb1b0a9d2 100644
--- a/source/slang/slang-ir.cpp
+++ b/source/slang/slang-ir.cpp
@@ -2081,7 +2081,32 @@ namespace Slang
         memset(&keyInst, 0, sizeof(keyInst));
         keyInst.m_op = kIROp_IntLit;
         keyInst.typeUse.usedValue = type;
-        keyInst.value.intVal = inValue;
+        // Truncate the input value based on `type`.
+        switch (type->getOp())
+        {
+        case kIROp_Int8Type:
+            keyInst.value.intVal = static_cast<int8_t>(inValue);
+            break;
+        case kIROp_Int16Type:
+            keyInst.value.intVal = static_cast<int16_t>(inValue);
+            break;
+        case kIROp_IntType:
+            keyInst.value.intVal = static_cast<int32_t>(inValue);
+            break;
+        case kIROp_UInt8Type:
+            keyInst.value.intVal = static_cast<uint8_t>(inValue);
+            break;
+        case kIROp_UInt16Type:
+            keyInst.value.intVal = static_cast<uint16_t>(inValue);
+            break;
+        case kIROp_BoolType:
+        case kIROp_UIntType:
+            keyInst.value.intVal = static_cast<uint32_t>(inValue);
+            break;
+        default:
+            keyInst.value.intVal = inValue;
+            break;
+        }
         return _findOrEmitConstant(keyInst);
     }
 
@@ -2091,7 +2116,20 @@ namespace Slang
         memset(&keyInst, 0, sizeof(keyInst));
         keyInst.m_op = kIROp_FloatLit;
         keyInst.typeUse.usedValue = type;
-        keyInst.value.floatVal = inValue;
+        // Truncate the input value based on `type`.
+        switch (type->getOp())
+        {
+        case kIROp_FloatType:
+            keyInst.value.floatVal = static_cast<float>(inValue);
+            break;
+        case kIROp_HalfType:
+            keyInst.value.floatVal = HalfToFloat(FloatToHalf((float)inValue));
+            break;
+        default:
+            keyInst.value.floatVal = inValue;
+            break;
+        }
+        
         return _findOrEmitConstant(keyInst);
     }
 
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