File: sext-load.ll

package info (click to toggle)
llvm-toolchain-14 1%3A14.0.6-12
  • links: PTS, VCS
  • area: main
  • in suites: bookworm
  • size: 1,496,180 kB
  • sloc: cpp: 5,593,972; ansic: 986,872; asm: 585,869; python: 184,223; objc: 72,530; lisp: 31,119; f90: 27,793; javascript: 9,780; pascal: 9,762; sh: 9,482; perl: 7,468; ml: 5,432; awk: 3,523; makefile: 2,538; xml: 953; cs: 573; fortran: 567
file content (30 lines) | stat: -rw-r--r-- 925 bytes parent folder | download | duplicates (14) 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
 
; RUN: llc < %s -mtriple=i686-- | FileCheck %s

; When doing sign extension, use the sext-load lowering to take advantage of
; x86's sign extension during loads.
;
; CHECK-LABEL: test1:
; CHECK:      movsbl {{.*}}, %eax
; CHECK-NEXT: ret
define i32 @test1(i32 %X) nounwind  {
entry:
	%tmp12 = trunc i32 %X to i8		; <i8> [#uses=1]
	%tmp123 = sext i8 %tmp12 to i32		; <i32> [#uses=1]
	ret i32 %tmp123
}

; When using a sextload representation, ensure that the sign extension is
; preserved even when removing shifted-out low bits.
;
; CHECK-LABEL: test2:
; CHECK:      movswl {{.*}}, %eax
; CHECK-NEXT: ret
define i32 @test2({i16, [6 x i8]}* %this) {
entry:
  %b48 = getelementptr inbounds { i16, [6 x i8] }, { i16, [6 x i8] }* %this, i32 0, i32 1
  %cast = bitcast [6 x i8]* %b48 to i48*
  %bf.load = load i48, i48* %cast, align 2
  %bf.ashr = ashr i48 %bf.load, 32
  %bf.cast = trunc i48 %bf.ashr to i32
  ret i32 %bf.cast
}