mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2025-02-01 05:01:59 +01:00
a018732b13
Summary:
Split off from D46031.
In masked merge case, this degrades IPC by decreasing instruction count.
{F6108777}
The next patch should be able to recover and improve this.
This also affects the transform @spatel have added in D27489 / rL289738,
and the test coverage for X86 was missing.
But after i have added it, and looked at the changes in MCA, i'm somewhat confused.
{F6093591} {F6093592} {F6093593}
I'd say this regression is an improvement, since `IPC` increased in that case?
Reviewers: spatel, craig.topper
Reviewed By: spatel
Subscribers: andreadb, llvm-commits, spatel
Differential Revision: https://reviews.llvm.org/D46493
llvm-svn: 331684
28 lines
919 B
LLVM
28 lines
919 B
LLVM
; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
|
|
; RUN: llc -mtriple=x86_64-unknown-linux-gnu -mattr=-bmi < %s | FileCheck %s --check-prefix=CHECK-NOBMI
|
|
; RUN: llc -mtriple=x86_64-unknown-linux-gnu -mattr=+bmi < %s | FileCheck %s --check-prefix=CHECK-BMI
|
|
|
|
; Optimize (x > -1) to (x >= 0) etc.
|
|
; Optimize (cmp (add / sub), 0): eliminate the subs used to update flag
|
|
; for comparison only
|
|
; rdar://10233472
|
|
|
|
define i32 @t1(i64 %a) {
|
|
; CHECK-NOBMI-LABEL: t1:
|
|
; CHECK-NOBMI: # %bb.0:
|
|
; CHECK-NOBMI-NEXT: xorl %eax, %eax
|
|
; CHECK-NOBMI-NEXT: testq %rdi, %rdi
|
|
; CHECK-NOBMI-NEXT: setns %al
|
|
; CHECK-NOBMI-NEXT: retq
|
|
;
|
|
; CHECK-BMI-LABEL: t1:
|
|
; CHECK-BMI: # %bb.0:
|
|
; CHECK-BMI-NEXT: xorl %eax, %eax
|
|
; CHECK-BMI-NEXT: testq %rdi, %rdi
|
|
; CHECK-BMI-NEXT: setns %al
|
|
; CHECK-BMI-NEXT: retq
|
|
%cmp = icmp sgt i64 %a, -1
|
|
%conv = zext i1 %cmp to i32
|
|
ret i32 %conv
|
|
}
|