From: Felix Fietkau Date: Thu, 17 Oct 2013 11:57:44 +0000 (+0000) Subject: gcc 4.8-linaro: backport an upstream fix to fix asm goto miscompilation X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=5b1e1eff73164e67854be8b39bd9f61645430000;p=openwrt%2Fstaging%2Fluka.git gcc 4.8-linaro: backport an upstream fix to fix asm goto miscompilation Signed-off-by: Felix Fietkau SVN-Revision: 38435 --- diff --git a/toolchain/gcc/patches/4.8-linaro/020-fix_pr58670.patch b/toolchain/gcc/patches/4.8-linaro/020-fix_pr58670.patch new file mode 100644 index 0000000000..8a4ae1b76e --- /dev/null +++ b/toolchain/gcc/patches/4.8-linaro/020-fix_pr58670.patch @@ -0,0 +1,167 @@ +--- a/gcc/cfgrtl.c ++++ b/gcc/cfgrtl.c +@@ -1784,10 +1784,18 @@ commit_one_edge_insertion (edge e) + } + + /* If the source has one successor and the edge is not abnormal, +- insert there. Except for the entry block. */ ++ insert there. Except for the entry block. ++ Don't do this if the predecessor ends in a jump other than ++ unconditional simple jump. E.g. for asm goto that points all ++ its labels at the fallthru basic block, we can't insert instructions ++ before the asm goto, as the asm goto can have various of side effects, ++ and can't emit instructions after the asm goto, as it must end ++ the basic block. */ + else if ((e->flags & EDGE_ABNORMAL) == 0 + && single_succ_p (e->src) +- && e->src != ENTRY_BLOCK_PTR) ++ && e->src != ENTRY_BLOCK_PTR ++ && (!JUMP_P (BB_END (e->src)) ++ || simplejump_p (BB_END (e->src)))) + { + bb = e->src; + +--- a/gcc/stmt.c ++++ b/gcc/stmt.c +@@ -613,6 +613,9 @@ tree_conflicts_with_clobbers_p (tree t, + CLOBBERS is a list of STRING_CST nodes each naming a hard register + that is clobbered by this insn. + ++ LABELS is a list of labels, and if LABELS is non-NULL, FALLTHRU_BB ++ should be the fallthru basic block of the asm goto. ++ + Not all kinds of lvalue that may appear in OUTPUTS can be stored directly. + Some elements of OUTPUTS may be replaced with trees representing temporary + values. The caller should copy those temporary values to the originally +@@ -622,7 +625,8 @@ tree_conflicts_with_clobbers_p (tree t, + + static void + expand_asm_operands (tree string, tree outputs, tree inputs, +- tree clobbers, tree labels, int vol, location_t locus) ++ tree clobbers, tree labels, basic_block fallthru_bb, ++ int vol, location_t locus) + { + rtvec argvec, constraintvec, labelvec; + rtx body; +@@ -643,6 +647,7 @@ expand_asm_operands (tree string, tree o + enum machine_mode *inout_mode = XALLOCAVEC (enum machine_mode, noutputs); + const char **constraints = XALLOCAVEC (const char *, noutputs + ninputs); + int old_generating_concat_p = generating_concat_p; ++ rtx fallthru_label = NULL_RTX; + + /* An ASM with no outputs needs to be treated as volatile, for now. */ + if (noutputs == 0) +@@ -942,8 +947,24 @@ expand_asm_operands (tree string, tree o + + /* Copy labels to the vector. */ + for (i = 0, tail = labels; i < nlabels; ++i, tail = TREE_CHAIN (tail)) +- ASM_OPERANDS_LABEL (body, i) +- = gen_rtx_LABEL_REF (Pmode, label_rtx (TREE_VALUE (tail))); ++ { ++ rtx r; ++ /* If asm goto has any labels in the fallthru basic block, use ++ a label that we emit immediately after the asm goto. Expansion ++ may insert further instructions into the same basic block after ++ asm goto and if we don't do this, insertion of instructions on ++ the fallthru edge might misbehave. See PR58670. */ ++ if (fallthru_bb ++ && label_to_block_fn (cfun, TREE_VALUE (tail)) == fallthru_bb) ++ { ++ if (fallthru_label == NULL_RTX) ++ fallthru_label = gen_label_rtx (); ++ r = fallthru_label; ++ } ++ else ++ r = label_rtx (TREE_VALUE (tail)); ++ ASM_OPERANDS_LABEL (body, i) = gen_rtx_LABEL_REF (Pmode, r); ++ } + + generating_concat_p = old_generating_concat_p; + +@@ -1067,6 +1088,9 @@ expand_asm_operands (tree string, tree o + emit_insn (body); + } + ++ if (fallthru_label) ++ emit_label (fallthru_label); ++ + /* For any outputs that needed reloading into registers, spill them + back to where they belong. */ + for (i = 0; i < noutputs; ++i) +@@ -1087,6 +1111,7 @@ expand_asm_stmt (gimple stmt) + const char *s; + tree str, out, in, cl, labels; + location_t locus = gimple_location (stmt); ++ basic_block fallthru_bb = NULL; + + /* Meh... convert the gimple asm operands into real tree lists. + Eventually we should make all routines work on the vectors instead +@@ -1122,6 +1147,9 @@ expand_asm_stmt (gimple stmt) + n = gimple_asm_nlabels (stmt); + if (n > 0) + { ++ edge fallthru = find_fallthru_edge (gimple_bb (stmt)->succs); ++ if (fallthru) ++ fallthru_bb = fallthru->dest; + t = labels = gimple_asm_label_op (stmt, 0); + for (i = 1; i < n; i++) + t = TREE_CHAIN (t) = gimple_asm_label_op (stmt, i); +@@ -1147,7 +1175,7 @@ expand_asm_stmt (gimple stmt) + + /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of + OUTPUTS some trees for where the values were actually stored. */ +- expand_asm_operands (str, outputs, in, cl, labels, ++ expand_asm_operands (str, outputs, in, cl, labels, fallthru_bb, + gimple_asm_volatile_p (stmt), locus); + + /* Copy all the intermediate outputs into the specified outputs. */ +--- /dev/null ++++ b/gcc/testsuite/gcc.dg/torture/pr58670.c +@@ -0,0 +1,47 @@ ++/* PR middle-end/58670 */ ++/* { dg-do run { target i?86-*-* x86_64-*-* } } */ ++ ++#if defined (__i386__) || defined (__x86_64__) ++#define ASM_STR "bts $1, %0; jc %l[lab]" ++#endif ++ ++__attribute__((noinline, noclone)) int ++foo (int a, int b) ++{ ++ if (a) ++ return -3; ++#ifdef ASM_STR ++ asm volatile goto (ASM_STR : : "m" (b) : "memory" : lab); ++ return 0; ++lab: ++#endif ++ return 0; ++} ++ ++int ++bar (int a, int b) ++{ ++ if (a) ++ return -3; ++#ifdef ASM_STR ++ asm volatile goto (ASM_STR : : "m" (b) : "memory" : lab); ++ return 0; ++lab: ++#endif ++ return 0; ++} ++ ++int ++main () ++{ ++ if (foo (1, 0) != -3 ++ || foo (0, 3) != 0 ++ || foo (1, 0) != -3 ++ || foo (0, 0) != 0 ++ || bar (1, 0) != -3 ++ || bar (0, 3) != 0 ++ || bar (1, 0) != -3 ++ || bar (0, 0) != 0) ++ __builtin_abort (); ++ return 0; ++}