[llvm] 83ccab3 - PeepholeOpt: Remove pointless check for subregister def (#128850)

[via llvm-commits]

Author: Matt Arsenault
Date: 2025-02-26T20:40:06+07:00
New Revision: 83ccab35d4ae2164fd3a8c039bcfcc0c8a5780bd

URL: https://github.com/llvm/llvm-project/commit/83ccab35d4ae2164fd3a8c039bcfcc0c8a5780bd
DIFF: https://github.com/llvm/llvm-project/commit/83ccab35d4ae2164fd3a8c039bcfcc0c8a5780bd.diff

LOG: PeepholeOpt: Remove pointless check for subregister def (#128850)

Subregister defs are illegal in SSA

Added: 
    

Modified: 
    llvm/lib/CodeGen/PeepholeOptimizer.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/CodeGen/PeepholeOptimizer.cpp b/llvm/lib/CodeGen/PeepholeOptimizer.cpp
index 44aec9bd0f157..cced54fa72819 100644
--- a/llvm/lib/CodeGen/PeepholeOptimizer.cpp
+++ b/llvm/lib/CodeGen/PeepholeOptimizer.cpp
@@ -2125,11 +2125,6 @@ ValueTrackerResult ValueTracker::getNextSourceFromPHI() {
   assert(Def->isPHI() && "Invalid definition");
   ValueTrackerResult Res;
 
-  // If we look for a 
diff erent subreg, bail as we do not support composing
-  // subregs yet.
-  if (Def->getOperand(0).getSubReg() != DefSubReg)
-    return ValueTrackerResult();
-
   // Return all register sources for PHI instructions.
   for (unsigned i = 1, e = Def->getNumOperands(); i < e; i += 2) {
     const MachineOperand &MO = Def->getOperand(i);