llvm-6502/test/CodeGen/Mips/i64arg.ll
Akira Hatanaka 6ff59a16a0 [mips] Make sure loads from lazy-binding entries do not get CSE'd or hoisted out
of loops.

Previously, two consecutive calls to function "func" would result in the
following sequence of instructions:

1. load $16, %got(func)($gp) // load address of lazy-binding stub.
2. move $25, $16
3. jalr $25                  // jump to lazy-binding stub.
4. nop
5. move $25, $16
6. jalr $25                  // jump to lazy-binding stub again.

With this patch, the second call directly jumps to func's address, bypassing
the lazy-binding resolution routine:

1. load $25, %got(func)($gp) // load address of lazy-binding stub.
2. jalr $25                  // jump to lazy-binding stub.
3. nop
4. load $25, %got(func)($gp) // load resolved address of func.
5. jalr $25                  // directly jump to func.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191591 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-28 00:12:32 +00:00

35 lines
1016 B
LLVM

; RUN: llc -march=mips < %s | FileCheck %s
define void @f1(i64 %ll1, float %f, i64 %ll, i32 %i, float %f2) nounwind {
entry:
; CHECK: move $[[R1:[0-9]+]], $5
; CHECK: move $[[R0:[0-9]+]], $4
; CHECK: ori $6, ${{[0-9]+}}, 3855
; CHECK: ori $7, ${{[0-9]+}}, 22136
; CHECK: lw $25, %call16(ff1)
; CHECK: jalr
tail call void @ff1(i32 %i, i64 1085102592623924856) nounwind
; CHECK-DAG: lw $25, %call16(ff2)
; CHECK-DAG: lw $[[R2:[0-9]+]], 80($sp)
; CHECK-DAG: lw $[[R3:[0-9]+]], 84($sp)
; CHECK-DAG: move $4, $[[R2]]
; CHECK-DAG: move $5, $[[R3]]
; CHECK: jalr $25
tail call void @ff2(i64 %ll, double 3.000000e+00) nounwind
%sub = add nsw i32 %i, -1
; CHECK-DAG: lw $25, %call16(ff3)
; CHECK-DAG: sw $[[R1]], 28($sp)
; CHECK-DAG: sw $[[R0]], 24($sp)
; CHECK-DAG: move $6, $[[R2]]
; CHECK-DAG: move $7, $[[R3]]
; CHECK: jalr $25
tail call void @ff3(i32 %i, i64 %ll, i32 %sub, i64 %ll1) nounwind
ret void
}
declare void @ff1(i32, i64)
declare void @ff2(i64, double)
declare void @ff3(i32, i64, i32, i64)