Compile the attached source code with options -Os -mthumb, gcc generates:
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push {r4, r5, r6, r7, lr}
sub sp, sp, #20
str r1, [sp, #8] // A
b .L10
.L13:
mov r0, r4
.L10:
ldr r1, [sp, #8]
add r3, r0, r1
...
Instruction A spills parameter into stack, it is always executed at the start
of the function, so it can be merged into the function prologue
push {r1, r4, r5, r6, r7, lr}
--
Summary: Parameter spilling can be merged into function prologue
Product: gcc
Version: 4.5.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: carrot at google dot com
GCC build triplet: i686-linux
GCC host triplet: i686-linux
GCC target triplet: arm-eabi
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42486
