[PATCH, alpha]: Fix g++.dg/other/pr22003.C ICE

[Uros Bizjak]

Hello!

This ICE exposes the problem with generation of thunks with 
-freorder-blocks-and-partition. The problem is, that function data, 
needed to switch sections (i.e. names of hot and cold sections), is not 
available any more after free_after_compilation is called throuh 
ASM_DECLARE_FUNCTION_SIZE macro (aka alpha_end_function). 
free_after_compilation is called in order to free data that was 
allocated by our specific way that thunks are generated (see 
alpha_emit_mi_thunk_osf). alpha_end_function that scans insn stream is 
called throuh ASM_DECLARE_FUNCTION_SIZE macro, so insn stream that is 
allocated by alpha_emit_mi_thunk can be released no earlier than after 
the insn scan loop in alpha_end_function.

However, when -freorder-blocks-and-partition is in effect, compilation 
still needs crtl data to output section labels and switch sections after 
ASM_DECLARE_FUNCTION_SIZE is called (see assemble_end_function in 
varasm.c). Calling free_after_compilation from alpha_end_function is 
thus wrong.

Attached patch fixes this problem by freeing just crtl->emit structure 
that is populated by alpha_emit_mi_thunk_osf, preserving other function 
data. The crtl structure is still cleared by "*clean_state" pass, so 
there is no leakage.

Also, emit_insn function needs insn locators (make insn_locator calls 
curr_insn_locator), so this patch moves insn locator initialization 
before the first call of emit_insn, and frees locators after all insn 
processing is done in alpha_end_function. Oh, and we are sure that 
alpha_output_mi_thunk_osf always processes thunks so assert is not needed ;)

2009-08-18  Uros Bizjak <ubizjak@gmail.com>

     * config/alpha/alpha.c (alpha_output_mi_thunk_osf): Allocate insn
     locators before emit_insn is called.  Remove assert that
     cfun->is_thunk.
     (alpha_end_function): Clear crtl->emit structure and free insn
     locators if cfun->is_thunk is true.

The patch was bootstrapped and regression tested on alphaev68-linux-gnu 
and fixes:

FAIL: g++.dg/other/pr22003.C (internal compiler error)
FAIL: g++.dg/other/pr22003.C (test for excess errors)

OK for mainline, 4.4 and 4.3 ?

Uros.
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