Re: [PATCH v8 4/8] ppc64 ftrace_with_regs configuration variables
From: Torsten Duwe <hidden>
Date: 2016-02-15 22:21:15
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lkml
On Mon, Feb 15, 2016 at 03:04:08PM +0100, Torsten Duwe wrote:
If you use "-pg -mprofile-kernel", gcc seems to forget that, and omits the TOC load, for a similar assembler calling sequence. Looking at the code I can _understand_ why this is so, but my GCC knowledge is not that deep that I could easily _fix_ this reliably.
Nonetheless, here's a proposal.
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c@@ -25154,6 +25154,10 @@ rs6000_emit_prologue (void) { cfun->machine->r2_setup_needed = df_regs_ever_live_p (TOC_REGNUM); + /* Profiling _will_ generate a call to a global _mcount. */ + if (crtl->profile) + cfun->machine->r2_setup_needed = true; + /* With -mminimal-toc we may generate an extra use of r2 below. */ if (TARGET_TOC && TARGET_MINIMAL_TOC && get_pool_size () != 0) cfun->machine->r2_setup_needed = true;