[llvm] fix isCall flag for JAL and JALR, and the isBranch flag for C_JR (PR #161105)

[Craig Topper via llvm-commits]

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@@ -752,13 +752,15 @@ def LUI : RVInstU<OPC_LUI, (outs GPR:$rd), (ins uimm20_lui:$imm20),
 def AUIPC : RVInstU<OPC_AUIPC, (outs GPR:$rd), (ins uimm20_auipc:$imm20),
                     "auipc", "$rd, $imm20">, Sched<[WriteIALU]>;
 
-def JAL : RVInstJ<OPC_JAL, (outs GPR:$rd), (ins simm21_lsb0_jal:$imm20),
-                  "jal", "$rd, $imm20">, Sched<[WriteJal]>;
+    let isCall = 1 in {
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topperc wrote:

Both of these instructions are not a call if the destination is X0. The RET pseudoinstruciton for example is JALR with rd=x0 and rs1=x0.

https://github.com/llvm/llvm-project/pull/161105