llvm-mirror/test/CodeGen/AArch64/fast-isel-erase.ll
Tim Northover 173f0949e5 FastIsel: take care to update iterators when removing instructions.
We keep a few iterators into the basic block we're selecting while
performing FastISel. Usually this is fine, but occasionally code wants
to remove already-emitted instructions. When this happens we have to be
careful to update those iterators so they're not pointint at dangling
memory.

llvm-svn: 349365
2018-12-17 17:25:53 +00:00

26 lines
618 B
LLVM

; RUN: llc -mtriple=arm64-apple-ios -o - %s -fast-isel=1 -O0 | FileCheck %s
; The zext can be folded into the load and removed, but doing so can invalidate
; pointers internal to FastISel and cause a crash so it must be done carefully.
define i32 @test() {
; CHECK-LABEL: test:
; CHECK: ldrh
; CHECK: bl _callee
; CHECK-NOT: uxth
entry:
store i32 undef, i32* undef, align 4
%t81 = load i16, i16* undef, align 2
call void @callee()
%t82 = zext i16 %t81 to i32
%t83 = shl i32 %t82, 16
%t84 = or i32 undef, %t83
br label %end
end:
%val = phi i32 [%t84, %entry]
ret i32 %val
}
declare void @callee()