middle-end/9760: Combine cannot do its job because immediate operand is used instead of register

middle-end/9760: Combine cannot do its job because immediate operand is used instead of register

[beszedes]

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>Number:         9760
>Category:       middle-end
>Synopsis:       Combine cannot do its job because immediate operand is used instead of register
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          pessimizes-code
>Submitter-Id:   net
>Arrival-Date:   Wed Feb 19 17:06:00 UTC 2003
>Closed-Date:
>Last-Modified:
>Originator:     Árpád Beszédes
>Release:        gcc version 3.3 20030217 (prerelease)
>Organization:
>Environment:
BUILD & HOST: Linux 2.4.20 i686 unknown
TARGET: arm-unknown-elf
>Description:
Combine cannot combine a shift and arithmetic insn into one insn in ARM target, because immediate is used as the second operand of the arithmetic and the combined ARM instruction can use only register for the source operand.
>How-To-Repeat:
gcc -Os -S 01.c

// 01.c

void func(char c, int t)
{
  ;
}
void foo(int u)
{
  func ( 8, (u >> 24) & 0xffL );
  func ( 8, (u >> 16) & 0xffL );
  func ( 8, (u >> 8) & 0xffL );
}
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted:
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