mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-13 20:32:21 +00:00
7c11695a23
When we have a parameter (or call site return) with a dereferenceable
attribute, it can specify the size of an array pointed to by that parameter. If
we have a value for which we can accumulate a constant offset to such a
parameter, then we can use that offset in a direct comparison with the size
specified by the dereferenceable attribute.
This enables us to handle cases like this:
int foo(int a[static 3]) {
return a[2]; /* this is always dereferenceable */
}
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213447 91177308-0d34-0410-b5e6-96231b3b80d8
169 lines
6.2 KiB
LLVM
169 lines
6.2 KiB
LLVM
; RUN: opt -S -basicaa -licm < %s | FileCheck %s
|
|
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
|
|
target triple = "x86_64-unknown-linux-gnu"
|
|
|
|
; This test represents the following function:
|
|
; void test1(int * __restrict__ a, int * __restrict__ b, int &c, int n) {
|
|
; for (int i = 0; i < n; ++i)
|
|
; if (a[i] > 0)
|
|
; a[i] = c*b[i];
|
|
; }
|
|
; and we want to hoist the load of %c out of the loop. This can be done only
|
|
; because the dereferenceable attribute is on %c.
|
|
|
|
; CHECK-LABEL: @test1
|
|
; CHECK: load i32* %c, align 4
|
|
; CHECK: for.body:
|
|
|
|
define void @test1(i32* noalias nocapture %a, i32* noalias nocapture readonly %b, i32* nocapture readonly nonnull dereferenceable(4) %c, i32 %n) #0 {
|
|
entry:
|
|
%cmp11 = icmp sgt i32 %n, 0
|
|
br i1 %cmp11, label %for.body, label %for.end
|
|
|
|
for.body: ; preds = %entry, %for.inc
|
|
%indvars.iv = phi i64 [ %indvars.iv.next, %for.inc ], [ 0, %entry ]
|
|
%arrayidx = getelementptr inbounds i32* %a, i64 %indvars.iv
|
|
%0 = load i32* %arrayidx, align 4
|
|
%cmp1 = icmp sgt i32 %0, 0
|
|
br i1 %cmp1, label %if.then, label %for.inc
|
|
|
|
if.then: ; preds = %for.body
|
|
%1 = load i32* %c, align 4
|
|
%arrayidx3 = getelementptr inbounds i32* %b, i64 %indvars.iv
|
|
%2 = load i32* %arrayidx3, align 4
|
|
%mul = mul nsw i32 %2, %1
|
|
store i32 %mul, i32* %arrayidx, align 4
|
|
br label %for.inc
|
|
|
|
for.inc: ; preds = %for.body, %if.then
|
|
%indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
|
|
%lftr.wideiv = trunc i64 %indvars.iv.next to i32
|
|
%exitcond = icmp eq i32 %lftr.wideiv, %n
|
|
br i1 %exitcond, label %for.end, label %for.body
|
|
|
|
for.end: ; preds = %for.inc, %entry
|
|
ret void
|
|
}
|
|
|
|
; This is the same as @test1, but without the dereferenceable attribute on %c.
|
|
; Without this attribute, we should not hoist the load of %c.
|
|
|
|
; CHECK-LABEL: @test2
|
|
; CHECK: if.then:
|
|
; CHECK: load i32* %c, align 4
|
|
|
|
define void @test2(i32* noalias nocapture %a, i32* noalias nocapture readonly %b, i32* nocapture readonly nonnull %c, i32 %n) #0 {
|
|
entry:
|
|
%cmp11 = icmp sgt i32 %n, 0
|
|
br i1 %cmp11, label %for.body, label %for.end
|
|
|
|
for.body: ; preds = %entry, %for.inc
|
|
%indvars.iv = phi i64 [ %indvars.iv.next, %for.inc ], [ 0, %entry ]
|
|
%arrayidx = getelementptr inbounds i32* %a, i64 %indvars.iv
|
|
%0 = load i32* %arrayidx, align 4
|
|
%cmp1 = icmp sgt i32 %0, 0
|
|
br i1 %cmp1, label %if.then, label %for.inc
|
|
|
|
if.then: ; preds = %for.body
|
|
%1 = load i32* %c, align 4
|
|
%arrayidx3 = getelementptr inbounds i32* %b, i64 %indvars.iv
|
|
%2 = load i32* %arrayidx3, align 4
|
|
%mul = mul nsw i32 %2, %1
|
|
store i32 %mul, i32* %arrayidx, align 4
|
|
br label %for.inc
|
|
|
|
for.inc: ; preds = %for.body, %if.then
|
|
%indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
|
|
%lftr.wideiv = trunc i64 %indvars.iv.next to i32
|
|
%exitcond = icmp eq i32 %lftr.wideiv, %n
|
|
br i1 %exitcond, label %for.end, label %for.body
|
|
|
|
for.end: ; preds = %for.inc, %entry
|
|
ret void
|
|
}
|
|
|
|
; This test represents the following function:
|
|
; void test3(int * restrict a, int * restrict b, int c[static 3], int n) {
|
|
; for (int i = 0; i < n; ++i)
|
|
; if (a[i] > 0)
|
|
; a[i] = c[2]*b[i];
|
|
; }
|
|
; and we want to hoist the load of c[2] out of the loop. This can be done only
|
|
; because the dereferenceable attribute is on %c.
|
|
|
|
; CHECK-LABEL: @test3
|
|
; CHECK: load i32* %c2, align 4
|
|
; CHECK: for.body:
|
|
|
|
define void @test3(i32* noalias nocapture %a, i32* noalias nocapture readonly %b, i32* nocapture readonly dereferenceable(12) %c, i32 %n) #0 {
|
|
entry:
|
|
%cmp11 = icmp sgt i32 %n, 0
|
|
br i1 %cmp11, label %for.body, label %for.end
|
|
|
|
for.body: ; preds = %entry, %for.inc
|
|
%indvars.iv = phi i64 [ %indvars.iv.next, %for.inc ], [ 0, %entry ]
|
|
%arrayidx = getelementptr inbounds i32* %a, i64 %indvars.iv
|
|
%0 = load i32* %arrayidx, align 4
|
|
%cmp1 = icmp sgt i32 %0, 0
|
|
br i1 %cmp1, label %if.then, label %for.inc
|
|
|
|
if.then: ; preds = %for.body
|
|
%c2 = getelementptr inbounds i32* %c, i64 2
|
|
%1 = load i32* %c2, align 4
|
|
%arrayidx3 = getelementptr inbounds i32* %b, i64 %indvars.iv
|
|
%2 = load i32* %arrayidx3, align 4
|
|
%mul = mul nsw i32 %2, %1
|
|
store i32 %mul, i32* %arrayidx, align 4
|
|
br label %for.inc
|
|
|
|
for.inc: ; preds = %for.body, %if.then
|
|
%indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
|
|
%lftr.wideiv = trunc i64 %indvars.iv.next to i32
|
|
%exitcond = icmp eq i32 %lftr.wideiv, %n
|
|
br i1 %exitcond, label %for.end, label %for.body
|
|
|
|
for.end: ; preds = %for.inc, %entry
|
|
ret void
|
|
}
|
|
|
|
; This is the same as @test3, but with a dereferenceable attribute on %c with a
|
|
; size too small to cover c[2] (and so we should not hoist it).
|
|
|
|
; CHECK-LABEL: @test4
|
|
; CHECK: if.then:
|
|
; CHECK: load i32* %c2, align 4
|
|
|
|
define void @test4(i32* noalias nocapture %a, i32* noalias nocapture readonly %b, i32* nocapture readonly dereferenceable(11) %c, i32 %n) #0 {
|
|
entry:
|
|
%cmp11 = icmp sgt i32 %n, 0
|
|
br i1 %cmp11, label %for.body, label %for.end
|
|
|
|
for.body: ; preds = %entry, %for.inc
|
|
%indvars.iv = phi i64 [ %indvars.iv.next, %for.inc ], [ 0, %entry ]
|
|
%arrayidx = getelementptr inbounds i32* %a, i64 %indvars.iv
|
|
%0 = load i32* %arrayidx, align 4
|
|
%cmp1 = icmp sgt i32 %0, 0
|
|
br i1 %cmp1, label %if.then, label %for.inc
|
|
|
|
if.then: ; preds = %for.body
|
|
%c2 = getelementptr inbounds i32* %c, i64 2
|
|
%1 = load i32* %c2, align 4
|
|
%arrayidx3 = getelementptr inbounds i32* %b, i64 %indvars.iv
|
|
%2 = load i32* %arrayidx3, align 4
|
|
%mul = mul nsw i32 %2, %1
|
|
store i32 %mul, i32* %arrayidx, align 4
|
|
br label %for.inc
|
|
|
|
for.inc: ; preds = %for.body, %if.then
|
|
%indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
|
|
%lftr.wideiv = trunc i64 %indvars.iv.next to i32
|
|
%exitcond = icmp eq i32 %lftr.wideiv, %n
|
|
br i1 %exitcond, label %for.end, label %for.body
|
|
|
|
for.end: ; preds = %for.inc, %entry
|
|
ret void
|
|
}
|
|
|
|
attributes #0 = { nounwind uwtable }
|
|
|