Fix pr6111: Avoid using the LR register for the target address of an indirect
branch in ARM v4 code, since it gets clobbered by the return address before
it is used. Instead of adding a new register class containing all the GPRs
except LR, just use the existing tGPR class.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96360 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMInstrInfo.td b/lib/Target/ARM/ARMInstrInfo.td
index 1c6f78a..a021388 100644
--- a/lib/Target/ARM/ARMInstrInfo.td
+++ b/lib/Target/ARM/ARMInstrInfo.td
@@ -828,9 +828,10 @@
}
// ARMv4T
- def BX : ABXIx2<(outs), (ins GPR:$func, variable_ops),
+ // Note: Restrict $func to the tGPR regclass to prevent it being in LR.
+ def BX : ABXIx2<(outs), (ins tGPR:$func, variable_ops),
IIC_Br, "mov\tlr, pc\n\tbx\t$func",
- [(ARMcall_nolink GPR:$func)]>,
+ [(ARMcall_nolink tGPR:$func)]>,
Requires<[IsARM, IsNotDarwin]> {
let Inst{7-4} = 0b0001;
let Inst{19-8} = 0b111111111111;
@@ -865,9 +866,10 @@
}
// ARMv4T
- def BXr9 : ABXIx2<(outs), (ins GPR:$func, variable_ops),
+ // Note: Restrict $func to the tGPR regclass to prevent it being in LR.
+ def BXr9 : ABXIx2<(outs), (ins tGPR:$func, variable_ops),
IIC_Br, "mov\tlr, pc\n\tbx\t$func",
- [(ARMcall_nolink GPR:$func)]>, Requires<[IsARM, IsDarwin]> {
+ [(ARMcall_nolink tGPR:$func)]>, Requires<[IsARM, IsDarwin]> {
let Inst{7-4} = 0b0001;
let Inst{19-8} = 0b111111111111;
let Inst{27-20} = 0b00010010;