1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-23 11:13:28 +01:00
llvm-mirror/test/CodeGen/PowerPC/repeated-fp-divisors.ll
Qiu Chaofan e59e06d663 [DAGCombiner] Require ninf for division estimation
Current implementation of division estimation isn't correct for some
cases like 1.0/0.0 (result is nan, not expected inf).

And this change exposes a potential infinite loop: we use
isConstOrConstSplatFP in combineRepeatedFPDivisors to look up if the
divisor is some constant. But it doesn't work after legalized on some
platforms. This patch restricts the method to act before LegalDAG.

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D80542
2020-06-14 22:58:22 +08:00

51 lines
2.1 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc -verify-machineinstrs -mtriple=powerpc64le-- < %s | FileCheck %s
; Check if this causes infinite loop when estimation disabled
define <4 x float> @repeated_fp_divisor_noest(float %a, <4 x float> %b) {
; CHECK-LABEL: repeated_fp_divisor_noest:
; CHECK: # %bb.0:
; CHECK-NEXT: xscvdpspn 0, 1
; CHECK-NEXT: addis 3, 2, .LCPI0_1@toc@ha
; CHECK-NEXT: addi 3, 3, .LCPI0_1@toc@l
; CHECK-NEXT: lvx 3, 0, 3
; CHECK-NEXT: addis 3, 2, .LCPI0_0@toc@ha
; CHECK-NEXT: addi 3, 3, .LCPI0_0@toc@l
; CHECK-NEXT: xxspltw 0, 0, 0
; CHECK-NEXT: xvdivsp 0, 35, 0
; CHECK-NEXT: lvx 3, 0, 3
; CHECK-NEXT: xvmulsp 1, 34, 35
; CHECK-NEXT: xvmulsp 34, 1, 0
; CHECK-NEXT: blr
%ins = insertelement <4 x float> undef, float %a, i32 0
%splat = shufflevector <4 x float> %ins, <4 x float> undef, <4 x i32> zeroinitializer
%t1 = fmul reassoc <4 x float> %b, <float 1.000000e+00, float 1.000000e+00, float 1.000000e+00, float 0x3FF028F5C0000000>
%mul = fdiv reassoc arcp nsz <4 x float> %t1, %splat
ret <4 x float> %mul
}
define <4 x float> @repeated_fp_divisor(float %a, <4 x float> %b) {
; CHECK-LABEL: repeated_fp_divisor:
; CHECK: # %bb.0:
; CHECK-NEXT: xscvdpspn 0, 1
; CHECK-NEXT: addis 3, 2, .LCPI1_0@toc@ha
; CHECK-NEXT: addi 3, 3, .LCPI1_0@toc@l
; CHECK-NEXT: lvx 3, 0, 3
; CHECK-NEXT: addis 3, 2, .LCPI1_1@toc@ha
; CHECK-NEXT: addi 3, 3, .LCPI1_1@toc@l
; CHECK-NEXT: lvx 4, 0, 3
; CHECK-NEXT: xxspltw 0, 0, 0
; CHECK-NEXT: xvresp 1, 0
; CHECK-NEXT: xvnmsubasp 35, 0, 1
; CHECK-NEXT: xvmulsp 0, 34, 36
; CHECK-NEXT: xvmaddasp 1, 1, 35
; CHECK-NEXT: xvmulsp 34, 0, 1
; CHECK-NEXT: blr
%ins = insertelement <4 x float> undef, float %a, i32 0
%splat = shufflevector <4 x float> %ins, <4 x float> undef, <4 x i32> zeroinitializer
%t1 = fmul reassoc <4 x float> %b, <float 1.000000e+00, float 1.000000e+00, float 1.000000e+00, float 0x3FF028F5C0000000>
%mul = fdiv reassoc arcp nsz ninf <4 x float> %t1, %splat
ret <4 x float> %mul
}