1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-26 12:43:36 +01:00
llvm-mirror/test/CodeGen/ARM/pr42062.ll
Diogo N. Sampaio 23ccb5de58 [ARM][FIX] Ran out of registers due tail recursion
Summary:
- pr42062
When compiling for MinSize,
ARMTargetLowering::LowerCall decides to indirect
multiple calls to a same function. However,
it disconsiders the limitation that thumb1
indirect calls require the callee to be in a
register from r0 to r3 (llvm limiation).
If all those registers are used by arguments, the
compiler dies with "error: run out of registers
during register allocation".
This patch tells the function
IsEligibleForTailCallOptimization if we intend to
perform indirect calls, as to avoid tail call
optimization.

Reviewers: dmgreen, efriedma

Reviewed By: efriedma

Subscribers: javed.absar, kristof.beyls, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62683

llvm-svn: 362366
2019-06-03 08:58:05 +00:00

39 lines
1.3 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc -o - %s 2>&1 | FileCheck %s --implicit-check-not=error
target triple = "thumbv8m.base-arm-none-eabi"
@foo = external global i8
declare i32 @bar(i8* nocapture, i32, i32, i8* nocapture)
define void @food(i8* %a) #0 {
; CHECK-LABEL: food:
; CHECK: mov [[ARG0:r[4-7]]], r0
; CHECK-NEXT: movs r1, #8
; CHECK-NEXT: movs r2, #1
; CHECK-NEXT: ldr [[FOO_R:r[4-7]]], [[FOO_ADDR:\..*]]
; CHECK-NEXT: ldr [[BAR_R:r[4-7]]], [[BAR_ADDR:\..*]]
; CHECK-NEXT: mov r3, [[FOO_R]]
; CHECK-NEXT: blx [[BAR_R]]
; CHECK-NEXT: movs r1, #9
; CHECK-NEXT: movs r2, #0
; CHECK-NEXT: mov r0, [[ARG0]]
; CHECK-NEXT: mov r3, [[FOO_R]]
; CHECK-NEXT: blx [[BAR_R]]
; CHECK-NEXT: movs r1, #7
; CHECK-NEXT: movs r2, #2
; CHECK-NEXT: mov r0, [[ARG0]]
; CHECK-NEXT: mov r3, [[FOO_R]]
; CHECK-NEXT: blx [[BAR_R]]
; CHECK-NEXT: pop {r4, r5, r6, pc}
; CHECK: [[FOO_ADDR]]:
; CHECK-NEXT: .long foo
; CHECK: [[BAR_ADDR]]:
; CHECK-NEXT: .long bar
entry:
%0 = tail call i32 @bar(i8* %a, i32 8, i32 1, i8* nonnull @foo)
%1 = tail call i32 @bar(i8* %a, i32 9, i32 0, i8* nonnull @foo)
%2 = tail call i32 @bar(i8* %a, i32 7, i32 2, i8* nonnull @foo)
ret void
}
attributes #0 = { minsize "target-cpu"="cortex-m23" }