[mips][FastISel] Allow computation of addresses from constant expressions.

Summary:
Try to compute addresses when the offset from a memory location is a constant
expression.

Based on a patch by Reed Kotler.

Test Plan:
Passes test-suite for -O0/O2 and mips 32 r1/r2

Reviewers: rkotler, dsanders

Subscribers: llvm-commits, aemerson, rfuhler

Differential Revision: http://reviews.llvm.org/D6767

llvm-svn: 237117
This commit is contained in:
Vasileios Kalintiris 2015-05-12 12:08:31 +00:00
parent 90476a5d90
commit 32cd69a2eb
2 changed files with 22 additions and 2 deletions

View File

@ -390,8 +390,10 @@ bool MipsFastISel::computeAddress(const Value *Obj, Address &Addr) {
Opcode = I->getOpcode();
U = I;
}
} else if (isa<ConstantExpr>(Obj))
return false;
} else if (const ConstantExpr *C = dyn_cast<ConstantExpr>(Obj)) {
Opcode = C->getOpcode();
U = C;
}
switch (Opcode) {
default:
break;

View File

@ -0,0 +1,18 @@
; RUN: llc -march=mipsel -mcpu=mips32 -relocation-model=pic \
; RUN: -fast-isel=true -mips-fast-isel -fast-isel-abort=1 < %s | FileCheck %s
; RUN: llc -march=mipsel -mcpu=mips32r2 -relocation-model=pic \
; RUN: -fast-isel=true -mips-fast-isel -fast-isel-abort=1 < %s | FileCheck %s
@ARR = external global [10 x i32], align 4
define void @foo() {
; CHECK-LABEL: foo
; CHECK-DAG: lw $[[ARR:[0-9]+]], %got(ARR)({{.*}})
; CHECK-DAG: addiu $[[T0:[0-9]+]], $zero, 12345
; CHECK: sw $[[T0]], 8($[[ARR]])
entry:
store i32 12345, i32* getelementptr inbounds ([10 x i32], [10 x i32]* @ARR, i32 0, i32 2), align 4
ret void
}