Files
clang-p2996/llvm/test/CodeGen/X86/pr12360.ll
Craig Topper b36cb20ef9 [X86] Teach X86TargetLowering::targetShrinkDemandedConstant to set non-demanded bits if it helps created an and mask that can be matched as a zero extend.
I had to modify the bswap recognition to allow unshrunk masks to make this work.

Fixes PR36689.

Differential Revision: https://reviews.llvm.org/D44442

llvm-svn: 327530
2018-03-14 16:55:15 +00:00

58 lines
1.3 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc < %s -mtriple=x86_64-apple-darwin | FileCheck %s
define zeroext i1 @f1(i8* %x) {
; CHECK-LABEL: f1:
; CHECK: ## %bb.0: ## %entry
; CHECK-NEXT: movb (%rdi), %al
; CHECK-NEXT: retq
entry:
%0 = load i8, i8* %x, align 1, !range !0
%tobool = trunc i8 %0 to i1
ret i1 %tobool
}
define zeroext i1 @f2(i8* %x) {
; CHECK-LABEL: f2:
; CHECK: ## %bb.0: ## %entry
; CHECK-NEXT: movb (%rdi), %al
; CHECK-NEXT: retq
entry:
%0 = load i8, i8* %x, align 1, !range !0
%tobool = icmp ne i8 %0, 0
ret i1 %tobool
}
!0 = !{i8 0, i8 2}
; check that we don't build a "trunc" from i1 to i1, which would assert.
define zeroext i1 @f3(i1 %x) {
; CHECK-LABEL: f3:
; CHECK: ## %bb.0: ## %entry
; CHECK-NEXT: andb $1, %dil
; CHECK-NEXT: movl %edi, %eax
; CHECK-NEXT: retq
entry:
%tobool = icmp ne i1 %x, 0
ret i1 %tobool
}
; check that we don't build a trunc when other bits are needed
define zeroext i1 @f4(i32 %x) {
; CHECK-LABEL: f4:
; CHECK: ## %bb.0: ## %entry
; CHECK-NEXT: movzwl %di, %eax
; CHECK-NEXT: shrl $15, %eax
; CHECK-NEXT: ## kill: def $al killed $al killed $eax
; CHECK-NEXT: retq
entry:
%y = and i32 %x, 32768
%z = icmp ne i32 %y, 0
ret i1 %z
}