[llvm] [SPARC][IAS] Add GNU extension for `addc` (PR #94245)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-mc

@llvm/pr-subscribers-backend-sparc

Author: Koakuma (koachan)

<details>
<summary>Changes</summary>

Transform `addc imm, %rs, %rd` into `addc %rs, imm, %rd`.
This is used in some GNU and Linux code.


---
Full diff: https://github.com/llvm/llvm-project/pull/94245.diff


2 Files Affected:

- (modified) llvm/lib/Target/Sparc/SparcInstrAliases.td (+8-3) 
- (modified) llvm/test/MC/Sparc/sparcv9-instructions.s (+10) 


``````````diff
diff --git a/llvm/lib/Target/Sparc/SparcInstrAliases.td b/llvm/lib/Target/Sparc/SparcInstrAliases.td
index db4c05cf18062..2b9244519f154 100644
--- a/llvm/lib/Target/Sparc/SparcInstrAliases.td
+++ b/llvm/lib/Target/Sparc/SparcInstrAliases.td
@@ -560,11 +560,16 @@ def : InstAlias<"mov $simm13, %tbr", (WRTBRri G0, simm13Op:$simm13), 0>;
 
 // End of Section A.3
 
-// or imm, reg, rd -> or reg, imm, rd
-// Nonstandard GNU extension.
-let EmitPriority = 0 in
+
+// Nonstandard GNU extensions.
+let EmitPriority = 0 in {
+  // or imm, reg, rd -> or reg, imm, rd
   def : InstAlias<"or $simm13, $rs1, $rd", (ORri IntRegs:$rd, IntRegs:$rs1, simm13Op:$simm13)>;
 
+  // addc/addx imm, reg, rd -> or reg, imm, rd
+  def : InstAlias<"addx $simm13, $rs1, $rd", (ADDCri IntRegs:$rd, IntRegs:$rs1, simm13Op:$simm13)>;
+}
+
 // wr reg_or_imm, specialreg -> wr %g0, reg_or_imm, specialreg
 // (aka: omit the first arg when it's g0. This is not in the manual, but is
 // supported by gnu and solaris as)
diff --git a/llvm/test/MC/Sparc/sparcv9-instructions.s b/llvm/test/MC/Sparc/sparcv9-instructions.s
index 0ca2e50989ca9..b947243f8258f 100644
--- a/llvm/test/MC/Sparc/sparcv9-instructions.s
+++ b/llvm/test/MC/Sparc/sparcv9-instructions.s
@@ -6,6 +6,16 @@
         ! V9:      addx %g2, %g1, %g3              ! encoding: [0x86,0x40,0x80,0x01]
         addc %g2, %g1, %g3
 
+        ! V8:      error: invalid instruction mnemonic
+        ! V8-NEXT: addc %g2, 1, %g3
+        ! V9:      addx %g2, 1, %g3              ! encoding: [0x86,0x40,0xa0,0x01]
+        addc %g2, 1, %g3
+
+        ! V8:      error: invalid instruction mnemonic
+        ! V8-NEXT: addc 1, %g2, %g3
+        ! V9:      addx %g2, 1, %g3              ! encoding: [0x86,0x40,0xa0,0x01]
+        addc 1, %g2, %g3
+
         ! V8:      error: invalid instruction mnemonic
         ! V8-NEXT: addccc %g1, %g2, %g3
         ! V9:      addxcc %g1, %g2, %g3            ! encoding: [0x86,0xc0,0x40,0x02]

``````````

</details>


https://github.com/llvm/llvm-project/pull/94245