From 6c5abe88bff9a4cd5abfa8bb793ecfdfc219a06b Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Sat, 26 Jun 2010 23:03:20 +0000 Subject: Implement rdar://7530813 - collapse multiple GEP instructions in IRgen This avoids generating two gep's for common array operations. Before we would generate something like: %tmp = load i32* %X.addr ; [#uses=1] %arraydecay = getelementptr inbounds [100 x i32]* %A, i32 0, i32 0 ; [#uses=1] %arrayidx = getelementptr inbounds i32* %arraydecay, i32 %tmp ; [#uses=1] %tmp1 = load i32* %arrayidx ; [#uses=1] Now we generate: %tmp = load i32* %X.addr ; [#uses=1] %arrayidx = getelementptr inbounds [100 x i32]* %A, i32 0, i32 %tmp ; [#uses=1] %tmp1 = load i32* %arrayidx ; [#uses=1] Less IR is better at -O0. llvm-svn: 106966 --- clang/test/CodeGen/exprs.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'clang/test/CodeGen/exprs.c') diff --git a/clang/test/CodeGen/exprs.c b/clang/test/CodeGen/exprs.c index d182ce81cab..010e6e3cf51 100644 --- a/clang/test/CodeGen/exprs.c +++ b/clang/test/CodeGen/exprs.c @@ -1,4 +1,4 @@ -// RUN: %clang_cc1 %s -emit-llvm -o - +// RUN: %clang_cc1 %s -emit-llvm -o - | FileCheck %s // PR1895 // sizeof function @@ -119,3 +119,15 @@ void f9(struct S *x) { void f10() { __builtin_sin(0); } + +// rdar://7530813 +// CHECK: define i32 @f11 +int f11(long X) { + int A[100]; + return A[X]; + +// CHECK: load {{.*}}* %X.addr +// CHECK-NEXT: getelementptr inbounds [100 x i32]* %A, i32 0, +// CHECK-NEXT: load i32* +} + -- cgit v1.2.3