[llvm] [AMDGPU] Set inst_pref_size to maximum (PR #126981)

[Matt Arsenault via llvm-commits]

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@@ -199,3 +201,28 @@ const MCExpr *SIProgramInfo::getPGMRSrc2(CallingConv::ID CC,
 
   return MCConstantExpr::create(0, Ctx);
 }
+
+uint64_t SIProgramInfo::getFunctionCodeSize(const MachineFunction &MF) {
+  if (!CodeSizeInBytes.has_value()) {
+    const GCNSubtarget &STM = MF.getSubtarget<GCNSubtarget>();
+    const SIInstrInfo *TII = STM.getInstrInfo();
+
+    uint64_t CodeSize = 0;
+
+    for (const MachineBasicBlock &MBB : MF) {
+      for (const MachineInstr &MI : MBB) {
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arsenm wrote:

Alignments not considered 

https://github.com/llvm/llvm-project/pull/126981