From a6e231bb2a7924f4269e6735d29a54b2318cd16c Mon Sep 17 00:00:00 2001
From: alexfh <alexfh@google.com>
Date: Tue, 19 Mar 2024 20:15:30 +0100
Subject: Revert "[Float2Int] Resolve FIXME: Pick the smallest legal type that
 fits" (#85843)

Reverts llvm/llvm-project#79158, which causes a miscompile. See
https://github.com/llvm/llvm-project/pull/79158#issuecomment-2007842032
---
 llvm/lib/Transforms/Scalar/Float2Int.cpp | 29 ++++++++++-------------------
 1 file changed, 10 insertions(+), 19 deletions(-)

(limited to 'llvm/lib')

diff --git a/llvm/lib/Transforms/Scalar/Float2Int.cpp b/llvm/lib/Transforms/Scalar/Float2Int.cpp
index 6ad4be169..ccca8bc 100644
--- a/llvm/lib/Transforms/Scalar/Float2Int.cpp
+++ b/llvm/lib/Transforms/Scalar/Float2Int.cpp
@@ -311,7 +311,7 @@ void Float2IntPass::walkForwards() {
 }
 
 // If there is a valid transform to be done, do it.
-bool Float2IntPass::validateAndTransform(const DataLayout &DL) {
+bool Float2IntPass::validateAndTransform() {
   bool MadeChange = false;
 
   // Iterate over every disjoint partition of the def-use graph.
@@ -376,24 +376,16 @@ bool Float2IntPass::validateAndTransform(const DataLayout &DL) {
       LLVM_DEBUG(dbgs() << "F2I: Value not guaranteed to be representable!\n");
       continue;
     }
-
-    // OK, R is known to be representable.
-    // Pick the smallest legal type that will fit.
-    Type *Ty = DL.getSmallestLegalIntType(*Ctx, MinBW);
-    if (!Ty) {
-      // Every supported target supports 64-bit and 32-bit integers,
-      // so fallback to a 32 or 64-bit integer if the value fits.
-      if (MinBW <= 32) {
-        Ty = Type::getInt32Ty(*Ctx);
-      } else if (MinBW <= 64) {
-        Ty = Type::getInt64Ty(*Ctx);
-      } else {
-        LLVM_DEBUG(dbgs() << "F2I: Value requires more than bits to represent "
-                             "than the target supports!\n");
-        continue;
-      }
+    if (MinBW > 64) {
+      LLVM_DEBUG(
+          dbgs() << "F2I: Value requires more than 64 bits to represent!\n");
+      continue;
     }
 
+    // OK, R is known to be representable. Now pick a type for it.
+    // FIXME: Pick the smallest legal type that will fit.
+    Type *Ty = (MinBW > 32) ? Type::getInt64Ty(*Ctx) : Type::getInt32Ty(*Ctx);
+
     for (auto MI = ECs.member_begin(It), ME = ECs.member_end();
          MI != ME; ++MI)
       convert(*MI, Ty);
@@ -499,8 +491,7 @@ bool Float2IntPass::runImpl(Function &F, const DominatorTree &DT) {
   walkBackwards();
   walkForwards();
 
-  const DataLayout &DL = F.getParent()->getDataLayout();
-  bool Modified = validateAndTransform(DL);
+  bool Modified = validateAndTransform();
   if (Modified)
     cleanup();
   return Modified;
-- 
cgit v1.1