[PATCH] D74213: [AVR] Don't adjust addresses by 2 for absolute values

[Ayke via Phabricator via llvm-commits]

aykevl updated this revision to Diff 246434.
aykevl edited the summary of this revision.
aykevl added a comment.

I found a way to test at least the case where the value should not be shifted. If it is shifted, the instruction becomes something other than a `nop`.
For the other case (when the value should be shifted), the AVR backend needs to be able to disassemble branch instructions.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D74213/new/

https://reviews.llvm.org/D74213

Files:
  llvm/lib/Target/AVR/MCTargetDesc/AVRAsmBackend.cpp
  llvm/test/MC/AVR/relocations-abs.s


Index: llvm/test/MC/AVR/relocations-abs.s
===================================================================
--- /dev/null
+++ llvm/test/MC/AVR/relocations-abs.s
@@ -0,0 +1,8 @@
+; RUN: llvm-mc -filetype=obj -triple=avr %s | llvm-objdump -dr - | FileCheck %s
+
+; CHECK: bar:
+; CHECK-NEXT: 00 00 nop
+; CHECK-NEXT: R_AVR_16 .text+0x2
+bar:
+    .short 1f
+1:
Index: llvm/lib/Target/AVR/MCTargetDesc/AVRAsmBackend.cpp
===================================================================
--- llvm/lib/Target/AVR/MCTargetDesc/AVRAsmBackend.cpp
+++ llvm/lib/Target/AVR/MCTargetDesc/AVRAsmBackend.cpp
@@ -244,8 +244,18 @@
   // To handle both cases, we simply un-adjust the temporary label
   // case so it acts like all other labels.
   if (const MCSymbolRefExpr *A = Target.getSymA()) {
-    if (A->getSymbol().isTemporary())
-      Value += 2;
+    if (A->getSymbol().isTemporary()) {
+      switch (Kind) {
+      case FK_Data_1:
+      case FK_Data_2:
+      case FK_Data_4:
+      case FK_Data_8:
+        // Don't shift value for absolute addresses.
+        break;
+      default:
+        Value += 2;
+      }
+    }
   }
 
   switch (Kind) {


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