Promote pointers to Pmode when passing/returning in registers is a security concern. This patch removes ix86_promote_function_mode, which exposes:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47725 There are 2 different patches for PR 47725: http://gcc.gnu.org/ml/gcc-patches/2011-02/threads.html#01018 One checks zero/sign extended hard registers in cant_combine_insn_p and the other changes assign_parm_setup_reg to copy the hard register first before extending it. This patch changes cant_combine_insn_p. H.J. ---- commit 6202f3601f5b2a5a41b60425f1206681823ecaa9 Author: H.J. Lu <hjl.to...@gmail.com> Date: Sun Jun 19 19:24:11 2011 -0700 Remove ix86_promote_function_mode. 2011-06-19 H.J. Lu <hongjiu...@intel.com> PR middle-end/47725 PR target/48085 * calls.c (precompute_register_parameters): Don't convert pointer to TLS symbol if needed. * combine.c (cant_combine_insn_p): Check zero/sign extended hard registers. * config/i386/i386.c (ix86_promote_function_mode): Removed. (TARGET_PROMOTE_FUNCTION_MODE): Likewise. diff --git a/gcc/ChangeLog.x32 b/gcc/ChangeLog.x32 index 564e123..6619f2f 100644 --- a/gcc/ChangeLog.x32 +++ b/gcc/ChangeLog.x32 @@ -1,3 +1,16 @@ +2011-06-19 H.J. Lu <hongjiu...@intel.com> + + PR middle-end/47725 + PR target/48085 + * calls.c (precompute_register_parameters): Don't convert + pointer to TLS symbol if needed. + + * combine.c (cant_combine_insn_p): Check zero/sign extended + hard registers. + + * config/i386/i386.c (ix86_promote_function_mode): Removed. + (TARGET_PROMOTE_FUNCTION_MODE): Likewise. + 2011-06-15 H.J. Lu <hongjiu...@intel.com> PR middle-end/48016 diff --git a/gcc/calls.c b/gcc/calls.c index 5a00d95..3d9a03f 100644 --- a/gcc/calls.c +++ b/gcc/calls.c @@ -706,13 +706,7 @@ precompute_register_parameters (int num_actuals, struct arg_data *args, pseudo now. TLS symbols sometimes need a call to resolve. */ if (CONSTANT_P (args[i].value) && !targetm.legitimate_constant_p (args[i].mode, args[i].value)) - { - if (GET_MODE (args[i].value) != args[i].mode) - args[i].value = convert_to_mode (args[i].mode, - args[i].value, - args[i].unsignedp); - args[i].value = force_reg (args[i].mode, args[i].value); - } + args[i].value = force_reg (args[i].mode, args[i].value); /* If we are to promote the function arg to a wider mode, do it now. */ diff --git a/gcc/combine.c b/gcc/combine.c index d3574a3..5512649 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -2168,6 +2168,12 @@ cant_combine_insn_p (rtx insn) return 0; src = SET_SRC (set); dest = SET_DEST (set); + if (GET_CODE (src) == ZERO_EXTEND + || GET_CODE (src) == SIGN_EXTEND) + src = XEXP (src, 0); + if (GET_CODE (dest) == ZERO_EXTEND + || GET_CODE (dest) == SIGN_EXTEND) + dest = XEXP (dest, 0); if (GET_CODE (src) == SUBREG) src = SUBREG_REG (src); if (GET_CODE (dest) == SUBREG) diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c index fa5ae97..104767b 100644 --- a/gcc/config/i386/i386.c +++ b/gcc/config/i386/i386.c @@ -7050,23 +7050,6 @@ ix86_function_value (const_tree valtype, const_tree fntype_or_decl, return ix86_function_value_1 (valtype, fntype_or_decl, orig_mode, mode); } -/* Pointer function arguments and return values are promoted to - Pmode. */ - -static enum machine_mode -ix86_promote_function_mode (const_tree type, enum machine_mode mode, - int *punsignedp, const_tree fntype, - int for_return) -{ - if (for_return != 1 && type != NULL_TREE && POINTER_TYPE_P (type)) - { - *punsignedp = POINTERS_EXTEND_UNSIGNED; - return Pmode; - } - return default_promote_function_mode (type, mode, punsignedp, fntype, - for_return); -} - rtx ix86_libcall_value (enum machine_mode mode) { @@ -35132,9 +35115,6 @@ ix86_autovectorize_vector_sizes (void) #undef TARGET_FUNCTION_VALUE_REGNO_P #define TARGET_FUNCTION_VALUE_REGNO_P ix86_function_value_regno_p -#undef TARGET_PROMOTE_FUNCTION_MODE -#define TARGET_PROMOTE_FUNCTION_MODE ix86_promote_function_mode - #undef TARGET_SECONDARY_RELOAD #define TARGET_SECONDARY_RELOAD ix86_secondary_reload
