[llvm] [IPSCCP][FuncSpec] Protect against metadata access from call args. (PR #124284)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-function-specialization

Author: David Green (davemgreen)

<details>
<summary>Changes</summary>

Fixes an issue reported from #<!-- -->114964, where metadata arguments were looked at to consider constants.

---
Full diff: https://github.com/llvm/llvm-project/pull/124284.diff


2 Files Affected:

- (modified) llvm/lib/Transforms/IPO/FunctionSpecialization.cpp (+2) 
- (added) llvm/test/Transforms/FunctionSpecialization/solver-constant-strictfpmetadata.ll (+17) 


``````````diff
diff --git a/llvm/lib/Transforms/IPO/FunctionSpecialization.cpp b/llvm/lib/Transforms/IPO/FunctionSpecialization.cpp
index 449d64d1614ff1..fa01156315741d 100644
--- a/llvm/lib/Transforms/IPO/FunctionSpecialization.cpp
+++ b/llvm/lib/Transforms/IPO/FunctionSpecialization.cpp
@@ -415,6 +415,8 @@ Constant *InstCostVisitor::visitCallBase(CallBase &I) {
 
   for (unsigned Idx = 0, E = I.getNumOperands() - 1; Idx != E; ++Idx) {
     Value *V = I.getOperand(Idx);
+    if (isa<MetadataAsValue>(V))
+      continue;
     Constant *C = findConstantFor(V);
     if (!C)
       return nullptr;
diff --git a/llvm/test/Transforms/FunctionSpecialization/solver-constant-strictfpmetadata.ll b/llvm/test/Transforms/FunctionSpecialization/solver-constant-strictfpmetadata.ll
new file mode 100644
index 00000000000000..99224b4efba6bc
--- /dev/null
+++ b/llvm/test/Transforms/FunctionSpecialization/solver-constant-strictfpmetadata.ll
@@ -0,0 +1,17 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt -passes=ipsccp -force-specialization -S < %s | FileCheck %s
+
+define float @test(ptr %this, float %cm, i1 %0) strictfp {
+; CHECK-LABEL: define float @test(
+; CHECK-SAME: ptr [[THIS:%.*]], float [[CM:%.*]], i1 [[TMP0:%.*]]) #[[ATTR0:[0-9]+]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[CMP:%.*]] = call i1 @llvm.experimental.constrained.fcmps.f32(float [[CM]], float 0.000000e+00, metadata !"ole", metadata !"fpexcept.strict")
+; CHECK-NEXT:    [[CALL295:%.*]] = call float @test.specialized.1(ptr null, float 0.000000e+00, i1 false)
+; CHECK-NEXT:    ret float 0.000000e+00
+;
+entry:
+  %cmp = call i1 @llvm.experimental.constrained.fcmps.f32(float %cm, float 0.000000e+00, metadata !"ole", metadata !"fpexcept.strict") #0
+  %call295 = call float @test(ptr null, float 0.000000e+00, i1 false) #0
+  ret float 0.000000e+00
+}
+

``````````

</details>


https://github.com/llvm/llvm-project/pull/124284