[llvm] r288515 - [x86] add tests to show missing demanded bits analysis; NFC
Sanjay Patel via llvm-commits
llvm-commits at lists.llvm.org
Fri Dec 2 09:48:48 PST 2016
Author: spatel
Date: Fri Dec 2 11:48:48 2016
New Revision: 288515
URL: http://llvm.org/viewvc/llvm-project?rev=288515&view=rev
Log:
[x86] add tests to show missing demanded bits analysis; NFC
Added:
llvm/trunk/test/CodeGen/X86/not-and-simplify.ll
Added: llvm/trunk/test/CodeGen/X86/not-and-simplify.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/not-and-simplify.ll?rev=288515&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/not-and-simplify.ll (added)
+++ llvm/trunk/test/CodeGen/X86/not-and-simplify.ll Fri Dec 2 11:48:48 2016
@@ -0,0 +1,53 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=-bmi | FileCheck %s --check-prefix=NO_BMI
+; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=+bmi | FileCheck %s --check-prefix=BMI
+
+; Clear high bits via shift, set them with xor (not), then mask them off.
+
+define i32 @shrink_xor_constant1(i32 %x) {
+; NO_BMI-LABEL: shrink_xor_constant1:
+; NO_BMI: # BB#0:
+; NO_BMI-NEXT: shrl $31, %edi
+; NO_BMI-NEXT: notl %edi
+; NO_BMI-NEXT: andl $1, %edi
+; NO_BMI-NEXT: movl %edi, %eax
+; NO_BMI-NEXT: retq
+;
+; BMI-LABEL: shrink_xor_constant1:
+; BMI: # BB#0:
+; BMI-NEXT: shrl $31, %edi
+; BMI-NEXT: movl $1, %eax
+; BMI-NEXT: andnl %eax, %edi, %eax
+; BMI-NEXT: retq
+;
+ %sh = lshr i32 %x, 31
+ %not = xor i32 %sh, -1
+ %and = and i32 %not, 1
+ ret i32 %and
+}
+
+; Clear low bits via shift, set them with xor (not), then mask them off.
+
+define i8 @shrink_xor_constant2(i8 %x) {
+; NO_BMI-LABEL: shrink_xor_constant2:
+; NO_BMI: # BB#0:
+; NO_BMI-NEXT: shlb $5, %dil
+; NO_BMI-NEXT: notb %dil
+; NO_BMI-NEXT: andb $-32, %dil
+; NO_BMI-NEXT: movl %edi, %eax
+; NO_BMI-NEXT: retq
+;
+; BMI-LABEL: shrink_xor_constant3:
+; BMI: # BB#0:
+; BMI-NEXT: shlb $5, %dil
+; BMI-NEXT: notb %dil
+; BMI-NEXT: andb $-32, %dil
+; BMI-NEXT: movl %edi, %eax
+; BMI-NEXT: retq
+;
+ %sh = shl i8 %x, 5
+ %not = xor i8 %sh, -1
+ %and = and i8 %not, 224 ; 0xE0
+ ret i8 %and
+}
+
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