[ValueTracking][NFC]: Use injected condition to compute known FPClass

[hassnaaHamdi]

No description provided.

[llvmbot]

@llvm/pr-subscribers-llvm-analysis

Author: Hassnaa Hamdi (hassnaaHamdi)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/139832.diff

2 Files Affected:

• (modified) llvm/include/llvm/Analysis/SimplifyQuery.h (+2)
• (modified) llvm/lib/Analysis/ValueTracking.cpp (+4)

diff --git a/llvm/include/llvm/Analysis/SimplifyQuery.h b/llvm/include/llvm/Analysis/SimplifyQuery.h
index e8f43c8c2e91f..063ca4eaa9db0 100644
--- a/llvm/include/llvm/Analysis/SimplifyQuery.h
+++ b/llvm/include/llvm/Analysis/SimplifyQuery.h
@@ -62,6 +62,8 @@ struct InstrInfoQuery {
 struct CondContext {
   Value *Cond;
   bool Invert = false;
+  // Condition is true if CxtI is in the true successor of Cond.
+  bool CondIsTrue = false;
   SmallPtrSet<Value *, 4> AffectedValues;
 
   CondContext(Value *Cond) : Cond(Cond) {}
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 3d403531cea2f..527e8c549c04f 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -5014,6 +5014,10 @@ static KnownFPClass computeKnownFPClassFromContext(const Value *V,
                                                    const SimplifyQuery &Q) {
   KnownFPClass KnownFromContext;
 
+  if (Q.CC && Q.CC->AffectedValues.contains(V))
+    computeKnownFPClassFromCond(V, Q.CC->Cond, 0, Q.CC->CondIsTrue,
+                                Q.CxtI, KnownFromContext);
+
   if (!Q.CxtI)
     return KnownFromContext;
 

[github-actions]

✅ With the latest revision this PR passed the C/C++ code formatter.

[hassnaaHamdi]

Hi @nikic
This patch is a response to your comments here: #119677

[nikic]

This is what Invert is for. (Or rather !Invert in this context.)

[nikic]

Suggested change

	computeKnownFPClassFromCond(V, Q.CC->Cond, 0, Q.CC->Invert, Q.CxtI,
	computeKnownFPClassFromCond(V, Q.CC->Cond, 0, !Q.CC->Invert, Q.CxtI,

This accepts CondIsTrue, so we should pass true for Invert=false.

[nikic]

LGTM