[PATCH] D76662: [PowerPC]: Don't allow r0 as a target for LD_GOT_TPREL_L/32

[Justin Hibbits via Phabricator via llvm-commits]

jhibbits created this revision.
jhibbits added a reviewer: PowerPC.
Herald added subscribers: llvm-commits, steven.zhang, shchenz, kbarton, hiraditya, krytarowski, arichardson, nemanjai, emaste.
Herald added a project: LLVM.

The linker is free to relax this (relocation R_PPC_GOT_TPREL16) against
R_PPC_TLS, if it sees fit (initial exec to local exec).  If r0 is used,
this can generate execution-invalid code (converts to 'addi %rX, %r0,
FOO, which translates in PPC-lingo to li %rX, FOO).  Forbid this
instead.

This fixes static binaries using locales on FreeBSD/powerpc
(tested on FreeBSD/powerpcspe).


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D76662

Files:
  llvm/lib/Target/PowerPC/PPCInstr64Bit.td
  llvm/lib/Target/PowerPC/PPCInstrInfo.td


Index: llvm/lib/Target/PowerPC/PPCInstrInfo.td
===================================================================
--- llvm/lib/Target/PowerPC/PPCInstrInfo.td
+++ llvm/lib/Target/PowerPC/PPCInstrInfo.td
@@ -3213,7 +3213,7 @@
 def PPC32PICGOT: PPCEmitTimePseudo<(outs gprc:$rD, gprc:$rT), (ins), "#PPC32PICGOT", 
                 []>, NoEncode<"$rT">;
 
-def LDgotTprelL32: PPCEmitTimePseudo<(outs gprc:$rD), (ins s16imm:$disp, gprc_nor0:$reg),
+def LDgotTprelL32: PPCEmitTimePseudo<(outs gprc_nor0:$rD), (ins s16imm:$disp, gprc_nor0:$reg),
                            "#LDgotTprelL32",
                            [(set i32:$rD,
                              (PPCldGotTprelL tglobaltlsaddr:$disp, i32:$reg))]>;
Index: llvm/lib/Target/PowerPC/PPCInstr64Bit.td
===================================================================
--- llvm/lib/Target/PowerPC/PPCInstr64Bit.td
+++ llvm/lib/Target/PowerPC/PPCInstr64Bit.td
@@ -1127,7 +1127,7 @@
                            (PPCaddisGotTprelHA i64:$reg,
                                                tglobaltlsaddr:$disp))]>,
                   isPPC64;
-def LDgotTprelL: PPCEmitTimePseudo<(outs g8rc:$rD), (ins s16imm64:$disp, g8rc_nox0:$reg),
+def LDgotTprelL: PPCEmitTimePseudo<(outs g8rc_nox0:$rD), (ins s16imm64:$disp, g8rc_nox0:$reg),
                         "#LDgotTprelL",
                         [(set i64:$rD,
                           (PPCldGotTprelL tglobaltlsaddr:$disp, i64:$reg))]>,


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