From 8dd04c8730327d7dc2fd29b43b8566fabbc3aa2c Mon Sep 17 00:00:00 2001
From: Yong He <yonghe@outlook.com>
Date: Tue, 9 Jan 2024 12:41:07 -0800
Subject: Fix funcs w/ buffer load being treated as readnone. (#3441)

Co-authored-by: Yong He <yhe@nvidia.com>
---
 .../slang/slang-ir-propagate-func-properties.cpp   | 37 ++++++++++++++++------
 1 file changed, 28 insertions(+), 9 deletions(-)

(limited to 'source')

diff --git a/source/slang/slang-ir-propagate-func-properties.cpp b/source/slang/slang-ir-propagate-func-properties.cpp
index df7869205..f186a3a57 100644
--- a/source/slang/slang-ir-propagate-func-properties.cpp
+++ b/source/slang/slang-ir-propagate-func-properties.cpp
@@ -14,6 +14,22 @@ public:
     virtual bool propagate(IRBuilder& builder, IRFunc* func) = 0;
 };
 
+static bool isResourceLoad(IROp op)
+{
+    switch (op)
+    {
+    case kIROp_ImageLoad:
+    case kIROp_StructuredBufferLoad:
+    case kIROp_ByteAddressBufferLoad:
+    case kIROp_StructuredBufferLoadStatus:
+    case kIROp_RWStructuredBufferLoad:
+    case kIROp_RWStructuredBufferLoadStatus:
+        return true;
+    default:
+        return false;
+    }
+}
+
 static bool isKnownOpCodeWithSideEffect(IROp op)
 {
     switch (op)
@@ -54,7 +70,7 @@ public:
 
     virtual bool propagate(IRBuilder& builder, IRFunc* f) override
     {
-        bool hasSideEffectCall = false;
+        bool hasReadNoneCall = false;
         for (auto block : f->getBlocks())
         {
             for (auto inst : block->getChildren())
@@ -62,11 +78,14 @@ public:
                 // Is this inst known to not have global side effect/analyzable?
                 if (!isKnownOpCodeWithSideEffect(inst->getOp()))
                 {
-                    if (inst->mightHaveSideEffects())
+                    if (inst->mightHaveSideEffects() || isResourceLoad(inst->getOp()))
                     {
-                        // We have a inst that has side effect and is not understood by this method.
+                        // We have a inst that has side effect that is not understood by this method,
                         // e.g. bufferStore, discard, etc.
-                        hasSideEffectCall = true;
+                        // or we are seeing a resource load.
+                        // These operations are not movable or removable,
+                        // and should not be treated as ReadNone.
+                        hasReadNoneCall = true;
                         break;
                     }
                 }
@@ -79,12 +98,12 @@ public:
                     default:
                         // We are calling an unknown function, so we have to assume
                         // there are side effects in the call.
-                        hasSideEffectCall = true;
+                        hasReadNoneCall = true;
                         break;
                     case kIROp_Func:
                         if (!callee->findDecoration<IRReadNoneDecoration>())
                         {
-                            hasSideEffectCall = true;
+                            hasReadNoneCall = true;
                             break;
                         }
                     }
@@ -102,16 +121,16 @@ public:
                         continue;
                     if (isGlobalOrUnknownMutableAddress(f, operand))
                     {
-                        hasSideEffectCall = true;
+                        hasReadNoneCall = true;
                         break;
                     }
                     break;
                 }
             }
-            if (hasSideEffectCall)
+            if (hasReadNoneCall)
                 break;
         }
-        if (!hasSideEffectCall)
+        if (!hasReadNoneCall)
         {
             builder.addDecoration(f, kIROp_ReadNoneDecoration);
             return true;
-- 
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