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Simon Pilgrim 1123f44663 [DAG] Fix shift amount limit in SimplifyDemandedBits trunc(shift(x,c)) to truncated bitwidth
We lost this in D56387/rG69bc0990a9181e6eb86228276d2f59435a7fae67 - where I got the src/dst bitwidths mixed up and assumed getValidShiftAmountConstant would catch it.

Patch by @craig.topper - confirmed by @Carrot that it fixes PR49162
2021-02-13 12:00:08 +00:00

34 lines
1.1 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc < %s -mtriple=i686-unknown-unknown | FileCheck %s --check-prefix=X86
; RUN: llc < %s -mtriple=x86_64-unknown-unknown | FileCheck %s --check-prefix=X64
define i32* @PR49162(i32* %base, i160* %ptr160) {
; X86-LABEL: PR49162:
; X86: # %bb.0:
; X86-NEXT: movl {{[0-9]+}}(%esp), %eax
; X86-NEXT: movl 8(%eax), %ecx
; X86-NEXT: shll $16, %ecx
; X86-NEXT: movl %ecx, %eax
; X86-NEXT: sarl $31, %eax
; X86-NEXT: shldl $16, %ecx, %eax
; X86-NEXT: shll $2, %eax
; X86-NEXT: addl {{[0-9]+}}(%esp), %eax
; X86-NEXT: retl
;
; X64-LABEL: PR49162:
; X64: # %bb.0:
; X64-NEXT: movl 8(%rsi), %eax
; X64-NEXT: shll $16, %eax
; X64-NEXT: cltq
; X64-NEXT: sarq $16, %rax
; X64-NEXT: leaq (%rdi,%rax,4), %rax
; X64-NEXT: retq
%load160 = load i160, i160* %ptr160, align 4
%shl = shl i160 %load160, 80
%ashr160 = ashr i160 %shl, 112
%trunc = trunc i160 %ashr160 to i64
%ashr64 = ashr i64 %trunc, 32
%gep = getelementptr inbounds i32, i32* %base, i64 %ashr64
ret i32* %gep
}