Includes documentation.
2018-07-25 Alan Hayward <alan.hayw...@arm.com>
* doc/rtl.texi (clobber_high): Add.
(parallel): Add in clobber high
* rtl.c (rtl_check_failed_code3): Add function.
* rtl.def (CLOBBER_HIGH): Add expression.
* rtl.h (RTL_CHECKC3): Add macro.
(rtl_check_failed_code3): Add declaration.
(XC3EXP): Add macro.
---
gcc/doc/rtl.texi | 15 ++++++++++++++-
gcc/rtl.c | 11 +++++++++++
gcc/rtl.def | 10 ++++++++++
gcc/rtl.h | 16 +++++++++++++++-
4 files changed, 50 insertions(+), 2 deletions(-)
diff --git a/gcc/doc/rtl.texi b/gcc/doc/rtl.texi
index a37d9ac5389..20c57732679 100644
--- a/gcc/doc/rtl.texi
+++ b/gcc/doc/rtl.texi
@@ -3296,6 +3296,18 @@ There is one other known use for clobbering a pseudo
register in a
clobbered by the insn. In this case, using the same pseudo register in
the clobber and elsewhere in the insn produces the expected results.
+@findex clobber_high
+@item (clobber_high @var{x})
+Represents the storing or possible storing of an unpredictable,
+undescribed value into the upper parts of @var{x}. The mode of the expression
+represents the lower parts of the register which will not be overwritten.
+@code{reg} must be a reg expression.
+
+One place this is used is when calling into functions where the registers are
+preserved, but only up to a given number of bits. For example when using
+Aarch64 SVE, calling a TLS descriptor will cause only the lower 128 bits of
+each of the vector registers to be preserved.
+
@findex use
@item (use @var{x})
Represents the use of the value of @var{x}. It indicates that the
@@ -3349,7 +3361,8 @@ Represents several side effects performed in parallel.
The square
brackets stand for a vector; the operand of @code{parallel} is a
vector of expressions. @var{x0}, @var{x1} and so on are individual
side effect expressions---expressions of code @code{set}, @code{call},
-@code{return}, @code{simple_return}, @code{clobber} or @code{use}.
+@code{return}, @code{simple_return}, @code{clobber} @code{use} or
+@code{clobber_high}.
``In parallel'' means that first all the values used in the individual
side-effects are computed, and second all the actual side-effects are
diff --git a/gcc/rtl.c b/gcc/rtl.c
index 90bbc7c6861..985db1c14f0 100644
--- a/gcc/rtl.c
+++ b/gcc/rtl.c
@@ -856,6 +856,17 @@ rtl_check_failed_code2 (const_rtx r, enum rtx_code code1,
enum rtx_code code2,
func, trim_filename (file), line);
}
+void
+rtl_check_failed_code3 (const_rtx r, enum rtx_code code1, enum rtx_code code2,
+ enum rtx_code code3, const char *file, int line,
+ const char *func)
+{
+ internal_error
+ ("RTL check: expected code '%s', '%s' or '%s', have '%s' in %s, at %s:%d",
+ GET_RTX_NAME (code1), GET_RTX_NAME (code2), GET_RTX_NAME (code3),
+ GET_RTX_NAME (GET_CODE (r)), func, trim_filename (file), line);
+}
+
void
rtl_check_failed_code_mode (const_rtx r, enum rtx_code code, machine_mode mode,
bool not_mode, const char *file, int line,
diff --git a/gcc/rtl.def b/gcc/rtl.def
index 2578a0ccb9e..0ed27505545 100644
--- a/gcc/rtl.def
+++ b/gcc/rtl.def
@@ -312,6 +312,16 @@ DEF_RTL_EXPR(USE, "use", "e", RTX_EXTRA)
is considered undeletable before reload. */
DEF_RTL_EXPR(CLOBBER, "clobber", "e", RTX_EXTRA)
+/* Indicate that the upper parts of something are clobbered in a way that we
+ don't want to explain. The MODE references the lower bits that will be
+ preserved. Anything above that size will be clobbered.
+
+ CLOBBER_HIGH only occurs as the operand of a PARALLEL rtx. It cannot appear
+ in other contexts, and unlike CLOBBER, it cannot appear on its own.
+ CLOBBER_HIGH can only be used with fixed register rtxes. */
+
+DEF_RTL_EXPR(CLOBBER_HIGH, "clobber_high", "e", RTX_EXTRA)
+
/* Call a subroutine.
Operand 1 is the address to call.
Operand 2 is the number of arguments. */
diff --git a/gcc/rtl.h b/gcc/rtl.h
index 565ce3abbe4..5e07e9bee80 100644
--- a/gcc/rtl.h
+++ b/gcc/rtl.h
@@ -1100,6 +1100,14 @@ is_a_helper <rtx_note *>::test (rtx_insn *insn)
__FUNCTION__); \
&_rtx->u.fld[_n]; }))
+#define RTL_CHECKC3(RTX, N, C1, C2, C3) __extension__ \
+(*({ __typeof (RTX) const _rtx = (RTX); const int _n = (N); \
+ const enum rtx_code _code = GET_CODE (_rtx); \
+ if (_code != (C1) && _code != (C2) && _code != (C3)) \
+ rtl_check_failed_code3 (_rtx, (C1), (C2), (C3), __FILE__, \
+ __LINE__, __FUNCTION__); \
+ &_rtx->u.fld[_n]; }))
+
#define RTVEC_ELT(RTVEC, I) __extension__ \
(*({ __typeof (RTVEC) const _rtvec = (RTVEC); const int _i = (I); \
if (_i < 0 || _i >= GET_NUM_ELEM (_rtvec))
\
@@ -1190,6 +1198,10 @@ extern void rtl_check_failed_code1 (const_rtx, enum
rtx_code, const char *,
extern void rtl_check_failed_code2 (const_rtx, enum rtx_code, enum rtx_code,
const char *, int, const char *)
ATTRIBUTE_NORETURN ATTRIBUTE_COLD;
+extern void rtl_check_failed_code3 (const_rtx, enum rtx_code, enum rtx_code,
+ enum rtx_code, const char *, int,
+ const char *)
+ ATTRIBUTE_NORETURN ATTRIBUTE_COLD;
extern void rtl_check_failed_code_mode (const_rtx, enum rtx_code, machine_mode,
bool, const char *, int, const char *)
ATTRIBUTE_NORETURN ATTRIBUTE_COLD;
@@ -1208,6 +1220,7 @@ extern void rtvec_check_failed_bounds (const_rtvec, int,
const char *, int,
#define RTL_CHECK2(RTX, N, C1, C2) ((RTX)->u.fld[N])
#define RTL_CHECKC1(RTX, N, C) ((RTX)->u.fld[N])
#define RTL_CHECKC2(RTX, N, C1, C2) ((RTX)->u.fld[N])
+#define RTL_CHECKC3(RTX, N, C1, C2, C3) ((RTX)->u.fld[N])
#define RTVEC_ELT(RTVEC, I) ((RTVEC)->elem[I])
#define XWINT(RTX, N) ((RTX)->u.hwint[N])
#define CWI_ELT(RTX, I) ((RTX)->u.hwiv.elem[I])
@@ -1362,6 +1375,7 @@ extern void rtl_check_failed_flag (const char *,
const_rtx, const char *,
#define XCVECLEN(RTX, N, C) GET_NUM_ELEM (XCVEC (RTX, N, C))
#define XC2EXP(RTX, N, C1, C2) (RTL_CHECKC2 (RTX, N, C1, C2).rt_rtx)
+#define XC3EXP(RTX, N, C1, C2, C3) (RTL_CHECKC3 (RTX, N, C1, C2, C3).rt_rtx)
/* Methods of rtx_expr_list. */
@@ -2632,7 +2646,7 @@ do {
\
/* For a SET rtx, SET_DEST is the place that is set
and SET_SRC is the value it is set to. */
-#define SET_DEST(RTX) XC2EXP (RTX, 0, SET, CLOBBER)
+#define SET_DEST(RTX) XC3EXP (RTX, 0, SET, CLOBBER, CLOBBER_HIGH)
#define SET_SRC(RTX) XCEXP (RTX, 1, SET)
#define SET_IS_RETURN_P(RTX) \
(RTL_FLAG_CHECK1 ("SET_IS_RETURN_P", (RTX), SET)->jump)
--
2.15.2 (Apple Git-101.1)
