[llvm] bb22aa8 - [IR] Slightly optimize getElementAsInteger() (#211550)

[via llvm-commits]

Author: Nikita Popov
Date: 2026-07-23T14:34:24Z
New Revision: bb22aa8127450930eb27215eb9f2c70acdee69fc

URL: https://github.com/llvm/llvm-project/commit/bb22aa8127450930eb27215eb9f2c70acdee69fc
DIFF: https://github.com/llvm/llvm-project/commit/bb22aa8127450930eb27215eb9f2c70acdee69fc.diff

LOG: [IR] Slightly optimize getElementAsInteger() (#211550)

This regressed with the introduction of the byte type, because
getElementPointer() calls getElementByteSize() calls
getPrimitiveSizeInBits(), but the switch used getScalarTypeInBits(),
which means we need to do two separate calls for the element size. Use
getElementByteSize() in both places so these can be CSEd.

Added: 
    

Modified: 
    llvm/lib/IR/Constants.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/IR/Constants.cpp b/llvm/lib/IR/Constants.cpp
index 39f5cbce32d9d..675cdaf6f1689 100644
--- a/llvm/lib/IR/Constants.cpp
+++ b/llvm/lib/IR/Constants.cpp
@@ -3373,15 +3373,15 @@ uint64_t ConstantDataSequential::getElementAsInteger(uint64_t Elt) const {
 
   // The data is stored in host byte order, make sure to cast back to the right
   // type to load with the right endianness.
-  switch (getElementType()->getScalarSizeInBits()) {
+  switch (getElementByteSize()) {
   default: llvm_unreachable("Invalid bitwidth for CDS");
-  case 8:
+  case 1:
     return *reinterpret_cast<const uint8_t *>(EltPtr);
-  case 16:
+  case 2:
     return *reinterpret_cast<const uint16_t *>(EltPtr);
-  case 32:
+  case 4:
     return *reinterpret_cast<const uint32_t *>(EltPtr);
-  case 64:
+  case 8:
     return *reinterpret_cast<const uint64_t *>(EltPtr);
   }
 }
@@ -3394,21 +3394,21 @@ APInt ConstantDataSequential::getElementAsAPInt(uint64_t Elt) const {
 
   // The data is stored in host byte order, make sure to cast back to the right
   // type to load with the right endianness.
-  switch (getElementType()->getScalarSizeInBits()) {
+  switch (getElementByteSize()) {
   default: llvm_unreachable("Invalid bitwidth for CDS");
-  case 8: {
+  case 1: {
     auto EltVal = *reinterpret_cast<const uint8_t *>(EltPtr);
     return APInt(8, EltVal);
   }
-  case 16: {
+  case 2: {
     auto EltVal = *reinterpret_cast<const uint16_t *>(EltPtr);
     return APInt(16, EltVal);
   }
-  case 32: {
+  case 4: {
     auto EltVal = *reinterpret_cast<const uint32_t *>(EltPtr);
     return APInt(32, EltVal);
   }
-  case 64: {
+  case 8: {
     auto EltVal = *reinterpret_cast<const uint64_t *>(EltPtr);
     return APInt(64, EltVal);
   }