common.opt (gas-loc-support, [...]): New.

	* common.opt (gas-loc-support, gas-locview-support): New.
	(ginline-points, ginternal-reset-location-views): New.
	* doc/invoke.texi: Document them.  Use @itemx where intended.
	(gvariable-location-views): Adjust.
	* target.def (reset_location_view): New.
	* doc/tm.texi.in (DWARF2_ASM_VIEW_DEBUG_INFO): New.
	(TARGET_RESET_LOCATION_VIEW): New.
	* doc/tm.texi: Rebuilt.
	* dwarf2out.c (dwarf2out_default_as_loc_support): New.
	(dwarf2out_default_as_locview_support): New.
	(output_asm_line_debug_info): Use option variables.
	(dwarf2out_maybe_output_loclist_view_pair): Likewise.
	(output_loc_list): Likewise.
	(add_high_low_attributes): Check option variables.
	Don't output entry view attribute in strict mode.
	(gen_inlined_subroutine_die): Check option variables.
	(dwarf2out_inline_entry): Likewise.
	(init_sections_and_labels): Likewise.
	(dwarf2out_early_finish): Likewise.
	(maybe_reset_location_view): New, from...
	(dwarf2out_var_location): ... here.  Call it.
	* debug.h (dwarf2out_default_as_loc_support): Declare.
	(dwarf2out_default_as_locview_support): Declare.
	* hooks.c (hook_int_rtx_insn_0): New.
	* hooks.h (hook_int_rtx_insn_0): Declare.
	* toplev.c (process_options): Take -gas-loc-support and
	-gas-locview-support from dwarf2out.  Enable
	-gvariable-location-views by default only with locview
	assembler support.  Enable -ginternal-reset-location-views by
	default only if the target defines the corresponding hook.
	Enable -ginline-points by default if location views are
	enabled; force it disabled if statement frontiers are
	disabled.
	* tree-inline.c (expand_call_inline): Check option variables.
	* tree-ssa-live.c (remove_unused_scope_block_p): Likewise.

From-SVN: r257631

13 files changed, 364 insertions, 93 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c582ae17c1c..f2a89589995 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,41 @@
+2018-02-13  Alexandre Oliva <aoliva@redhat.com>
+
+	* common.opt (gas-loc-support, gas-locview-support): New.
+	(ginline-points, ginternal-reset-location-views): New.
+	* doc/invoke.texi: Document them.  Use @itemx where intended.
+	(gvariable-location-views): Adjust.
+	* target.def (reset_location_view): New.
+	* doc/tm.texi.in (DWARF2_ASM_VIEW_DEBUG_INFO): New.
+	(TARGET_RESET_LOCATION_VIEW): New.
+	* doc/tm.texi: Rebuilt.
+	* dwarf2out.c (dwarf2out_default_as_loc_support): New.
+	(dwarf2out_default_as_locview_support): New.
+	(output_asm_line_debug_info): Use option variables.
+	(dwarf2out_maybe_output_loclist_view_pair): Likewise.
+	(output_loc_list): Likewise.
+	(add_high_low_attributes): Check option variables.
+	Don't output entry view attribute in strict mode.
+	(gen_inlined_subroutine_die): Check option variables.
+	(dwarf2out_inline_entry): Likewise.
+	(init_sections_and_labels): Likewise.
+	(dwarf2out_early_finish): Likewise.
+	(maybe_reset_location_view): New, from...
+	(dwarf2out_var_location): ... here.  Call it.
+	* debug.h (dwarf2out_default_as_loc_support): Declare.
+	(dwarf2out_default_as_locview_support): Declare.
+	* hooks.c (hook_int_rtx_insn_0): New.
+	* hooks.h (hook_int_rtx_insn_0): Declare.
+	* toplev.c (process_options): Take -gas-loc-support and
+	-gas-locview-support from dwarf2out.  Enable
+	-gvariable-location-views by default only with locview
+	assembler support.  Enable -ginternal-reset-location-views by
+	default only if the target defines the corresponding hook.
+	Enable -ginline-points by default if location views are
+	enabled; force it disabled if statement frontiers are
+	disabled.
+	* tree-inline.c (expand_call_inline): Check option variables.
+	* tree-ssa-live.c (remove_unused_scope_block_p): Likewise.
+
 2018-02-13  Richard Sandiford  <richard.sandiford@linaro.org>
 
 	PR tree-optimization/84321
diff --git a/gcc/common.opt b/gcc/common.opt
index 40ec0088c57..e0bc4d1bb18 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -2880,6 +2880,14 @@ g
 Common Driver RejectNegative JoinedOrMissing
 Generate debug information in default format.
 
+gas-loc-support
+Common Driver Var(dwarf2out_as_loc_support) Init(2)
+Assume assembler support for (DWARF2+) .loc directives
+
+gas-locview-support
+Common Driver Var(dwarf2out_as_locview_support) Init(2)
+Assume assembler support for view in (DWARF2+) .loc directives
+
 gcoff
 Common Driver Ignore Warn(switch %qs no longer supported)
 Does nothing.  Preserved for backward compatibility.
@@ -2912,6 +2920,14 @@ ggdb
 Common Driver JoinedOrMissing
 Generate debug information in default extended format.
 
+ginline-points
+Common Driver Var(debug_inline_points) Init(2)
+Generate extended entry point information for inlined functions
+
+ginternal-reset-location-views
+Common Driver Var(debug_internal_reset_location_views) Init(2)
+Compute locview reset points based on insn length estimates
+
 gno-
 RejectNegative Joined Undocumented
 ; Catch the gno- prefix, so it doesn't backtrack to g<level>.
diff --git a/gcc/debug.h b/gcc/debug.h
index e1dfe4befaa..126e56e8c8d 100644
--- a/gcc/debug.h
+++ b/gcc/debug.h
@@ -248,6 +248,8 @@ extern bool dwarf2out_do_eh_frame (void);
 extern bool dwarf2out_do_frame (void);
 extern bool dwarf2out_do_cfi_asm (void);
 extern void dwarf2out_switch_text_section (void);
+extern bool dwarf2out_default_as_loc_support (void);
+extern bool dwarf2out_default_as_locview_support (void);
 
 /* For -fdump-go-spec.  */
 
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 9db9d083a47..48194c825f3 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -346,9 +346,13 @@ Objective-C and Objective-C++ Dialects}.
 @gccoptlist{-g  -g@var{level}  -gdwarf  -gdwarf-@var{version} @gol
 -ggdb  -grecord-gcc-switches  -gno-record-gcc-switches @gol
 -gstabs  -gstabs+  -gstrict-dwarf  -gno-strict-dwarf @gol
+-gas-loc-support  -gno-as-loc-support @gol
+-gas-locview-support  -gno-as-locview-support @gol
 -gcolumn-info  -gno-column-info @gol
 -gstatement-frontiers  -gno-statement-frontiers @gol
 -gvariable-location-views  -gno-variable-location-views @gol
+-ginternal-reset-location-views  -gno-internal-reset-location-views @gol
+-ginline-points  -gno-inline-points @gol
 -gvms  -gxcoff  -gxcoff+  -gz@r{[}=@var{type}@r{]} @gol
 -fdebug-prefix-map=@var{old}=@var{new}  -fdebug-types-section @gol
 -fno-eliminate-unused-debug-types @gol
@@ -4159,7 +4163,7 @@ result in false positives.
 
 @table @gcctabopt
 @item -Wformat-overflow
-@item -Wformat-overflow=1
+@itemx -Wformat-overflow=1
 @opindex Wformat-overflow
 @opindex Wno-format-overflow
 Level @var{1} of @option{-Wformat-overflow} enabled by @option{-Wformat}
@@ -4278,7 +4282,7 @@ logic @option{-Wformat-overflow}.
 
 @table @gcctabopt
 @item -Wformat-truncation
-@item -Wformat-truncation=1
+@itemx -Wformat-truncation=1
 @opindex Wformat-truncation
 @opindex Wno-format-overflow
 Level @var{1} of @option{-Wformat-truncation} enabled by @option{-Wformat}
@@ -5239,7 +5243,7 @@ Option @option{-Wstringop-overflow=2} is enabled by default.
 
 @table @gcctabopt
 @item -Wstringop-overflow
-@item -Wstringop-overflow=1
+@itemx -Wstringop-overflow=1
 @opindex Wstringop-overflow
 @opindex Wno-stringop-overflow
 The @option{-Wstringop-overflow=1} option uses type-zero Object Size Checking
@@ -7214,7 +7218,7 @@ and on some objects @code{.debug_types} produces larger instead of smaller
 debugging information.
 
 @item -grecord-gcc-switches
-@item -gno-record-gcc-switches
+@itemx -gno-record-gcc-switches
 @opindex grecord-gcc-switches
 @opindex gno-record-gcc-switches
 This switch causes the command-line options used to invoke the
@@ -7237,8 +7241,38 @@ DWARF extensions from later standard versions is allowed.
 Allow using extensions of later DWARF standard version than selected with
 @option{-gdwarf-@var{version}}.
 
+@item -gas-loc-support
+@opindex gas-loc-support
+Inform the compiler that the assembler supports @code{.loc} directives.
+It may then use them for the assembler to generate DWARF2+ line number
+tables.
+
+This is generally desirable, because assembler-generated line-number
+tables are a lot more compact than those the compiler can generate
+itself.
+
+This option will be enabled by default if, at GCC configure time, the
+assembler was found to support such directives.
+
+@item -gno-as-loc-support
+@opindex gno-as-loc-support
+Force GCC to generate DWARF2+ line number tables internally, if DWARF2+
+line number tables are to be generated.
+
+@item gas-locview-support
+@opindex gas-locview-support
+Inform the compiler that the assembler supports @code{view} assignment
+and reset assertion checking in @code{.loc} directives.
+
+This option will be enabled by default if, at GCC configure time, the
+assembler was found to support them.
+
+@item gno-as-locview-support
+Force GCC to assign view numbers internally, if
+@option{-gvariable-location-views} are explicitly requested.
+
 @item -gcolumn-info
-@item -gno-column-info
+@itemx -gno-column-info
 @opindex gcolumn-info
 @opindex gno-column-info
 Emit location column information into DWARF debugging information, rather
@@ -7246,7 +7280,7 @@ than just file and line.
 This option is enabled by default.
 
 @item -gstatement-frontiers
-@item -gno-statement-frontiers
+@itemx -gno-statement-frontiers
 @opindex gstatement-frontiers
 @opindex gno-statement-frontiers
 This option causes GCC to create markers in the internal representation
@@ -7257,8 +7291,8 @@ compiling with optimization (@option{-Os}, @option{-O}, @option{-O2},
 @dots{}), and outputting DWARF 2 debug information at the normal level.
 
 @item -gvariable-location-views
-@item -gvariable-location-views=incompat5
-@item -gno-variable-location-views
+@itemx -gvariable-location-views=incompat5
+@itemx -gno-variable-location-views
 @opindex gvariable-location-views
 @opindex gvariable-location-views=incompat5
 @opindex gno-variable-location-views
@@ -7272,9 +7306,15 @@ which generally makes them somewhat less compact.  The augmented line
 number tables and location lists are fully backward-compatible, so they
 can be consumed by debug information consumers that are not aware of
 these augmentations, but they won't derive any benefit from them either.
+
 This is enabled by default when outputting DWARF 2 debug information at
-the normal level, as long as @option{-fvar-tracking-assignments} is
-enabled and @option{-gstrict-dwarf} is not.
+the normal level, as long as there is assembler support,
+@option{-fvar-tracking-assignments} is enabled and
+@option{-gstrict-dwarf} is not.  When assembler support is not
+available, this may still be enabled, but it will force GCC to output
+internal line number tables, and if
+@option{-ginternal-reset-location-views} is not enabled, that will most
+certainly lead to silently mismatching location views.
 
 There is a proposed representation for view numbers that is not backward
 compatible with the location list format introduced in DWARF 5, that can
@@ -7284,6 +7324,30 @@ implementation of the proposed representation.  Debug information
 consumers are not expected to support this extended format, and they
 would be rendered unable to decode location lists using it.
 
+@item -ginternal-reset-location-views
+@itemx -gnointernal-reset-location-views
+@opindex ginternal-reset-location-views
+@opindex gno-internal-reset-location-views
+Attempt to determine location views that can be omitted from location
+view lists.  This requires the compiler to have very accurate insn
+length estimates, which isn't always the case, and it may cause
+incorrect view lists to be generated silently when using an assembler
+that does not support location view lists.  The GNU assembler will flag
+any such error as a @code{view number mismatch}.  This is only enabled
+on ports that define a reliable estimation function.
+
+@item -ginline-points
+@itemx -gno-inline-points
+@opindex ginline-points
+@opindex gno-inline-points
+Generate extended debug information for inlined functions.  Location
+view tracking markers are inserted at inlined entry points, so that
+address and view numbers can be computed and output in debug
+information.  This can be enabled independently of location views, in
+which case the view numbers won't be output, but it can only be enabled
+along with statement frontiers, and it is only enabled by default if
+location views are enabled.
+
 @item -gz@r{[}=@var{type}@r{]}
 @opindex gz
 Produce compressed debug sections in DWARF format, if that is supported.
@@ -10043,7 +10107,7 @@ also use other heuristics to decide whether if-conversion is likely to be
 profitable.
 
 @item max-rtl-if-conversion-predictable-cost
-@item max-rtl-if-conversion-unpredictable-cost
+@itemx max-rtl-if-conversion-unpredictable-cost
 RTL if-conversion will try to remove conditional branches around a block
 and replace them with conditionally executed instructions.  These parameters
 give the maximum permissible cost for the sequence that would be generated
@@ -10768,7 +10832,7 @@ parameters only when their cumulative size is less or equal to
 pointer parameter.
 
 @item sra-max-scalarization-size-Ospeed
-@item sra-max-scalarization-size-Osize
+@itemx sra-max-scalarization-size-Osize
 The two Scalar Reduction of Aggregates passes (SRA and IPA-SRA) aim to
 replace scalar parts of aggregates with uses of independent scalar
 variables.  These parameters control the maximum size, in storage units,
@@ -14545,7 +14609,7 @@ This erratum workaround is made at link time and this will only pass the
 corresponding flag to the linker.
 
 @item -mlow-precision-recip-sqrt
-@item -mno-low-precision-recip-sqrt
+@itemx -mno-low-precision-recip-sqrt
 @opindex mlow-precision-recip-sqrt
 @opindex mno-low-precision-recip-sqrt
 Enable or disable the reciprocal square root approximation.
@@ -14555,7 +14619,7 @@ precision of reciprocal square root results to about 16 bits for
 single precision and to 32 bits for double precision.
 
 @item -mlow-precision-sqrt
-@item -mno-low-precision-sqrt
+@itemx -mno-low-precision-sqrt
 @opindex -mlow-precision-sqrt
 @opindex -mno-low-precision-sqrt
 Enable or disable the square root approximation.
@@ -14566,7 +14630,7 @@ single precision and to 32 bits for double precision.
 If enabled, it implies @option{-mlow-precision-recip-sqrt}.
 
 @item -mlow-precision-div
-@item -mno-low-precision-div
+@itemx -mno-low-precision-div
 @opindex -mlow-precision-div
 @opindex -mno-low-precision-div
 Enable or disable the division approximation.
@@ -20194,7 +20258,7 @@ for regression testing of mixed MIPS16/non-MIPS16 code generation, and is
 not intended for ordinary use in compiling user code.
 
 @item -minterlink-compressed
-@item -mno-interlink-compressed
+@itemx -mno-interlink-compressed
 @opindex minterlink-compressed
 @opindex mno-interlink-compressed
 Require (do not require) that code using the standard (uncompressed) MIPS ISA
@@ -20775,7 +20839,7 @@ Tell the MIPS assembler to not run its preprocessor over user
 assembler files (with a @samp{.s} suffix) when assembling them.
 
 @item -mfix-24k
-@item -mno-fix-24k
+@itemx -mno-fix-24k
 @opindex mfix-24k
 @opindex mno-fix-24k
 Work around the 24K E48 (lost data on stores during refill) errata.
@@ -21535,7 +21599,7 @@ into the small data or BSS sections instead of the normal data or BSS
 sections.  The default value of @var{num} is 8.
 
 @item -mgpopt=@var{option}
-@item -mgpopt
+@itemx -mgpopt
 @itemx -mno-gpopt
 @opindex mgpopt
 @opindex mno-gpopt
@@ -23094,7 +23158,7 @@ or 32 bits (@option{-m32bit-doubles}) in size.  The default is
 @option{-m32bit-doubles}.
 
 @item -msave-mduc-in-interrupts
-@item -mno-save-mduc-in-interrupts
+@itemx -mno-save-mduc-in-interrupts
 @opindex msave-mduc-in-interrupts
 @opindex mno-save-mduc-in-interrupts
 Specifies that interrupt handler functions should preserve the
@@ -26727,13 +26791,13 @@ comparisons.  These correctly handle the case where the result of a
 comparison is unordered.
 
 @item -m80387
-@item -mhard-float
+@itemx -mhard-float
 @opindex 80387
 @opindex mhard-float
 Generate output containing 80387 instructions for floating point.
 
 @item -mno-80387
-@item -msoft-float
+@itemx -msoft-float
 @opindex no-80387
 @opindex msoft-float
 Generate output containing library calls for floating point.
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index ddf48cb4b4d..bd8b917ba82 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -9966,6 +9966,29 @@ line debug info sections.  This will result in much more compact line number
 tables, and hence is desirable if it works.
 @end defmac
 
+@defmac DWARF2_ASM_VIEW_DEBUG_INFO
+Define this macro to be a nonzero value if the assembler supports view
+assignment and verification in @code{.loc}.  If it does not, but the
+user enables location views, the compiler may have to fallback to
+internal line number tables.
+@end defmac
+
+@deftypefn {Target Hook} int TARGET_RESET_LOCATION_VIEW (rtx_insn *@var{})
+This hook, if defined, enables -ginternal-reset-location-views, and
+uses its result to override cases in which the estimated min insn
+length might be nonzero even when a PC advance (i.e., a view reset)
+cannot be taken for granted.
+
+If the hook is defined, it must return a positive value to indicate
+the insn definitely advances the PC, and so the view number can be
+safely assumed to be reset; a negative value to mean the insn
+definitely does not advance the PC, and os the view number must not
+be reset; or zero to decide based on the estimated insn length.
+
+If insn length is to be regarded as reliable, set the hook to
+@code{hook_int_rtx_insn_0}.
+@end deftypefn
+
 @deftypevr {Target Hook} bool TARGET_WANT_DEBUG_PUB_SECTIONS
 True if the @code{.debug_pubtypes} and @code{.debug_pubnames} sections should be emitted.  These sections are not used on most platforms, and in particular GDB does not use them.
 @end deftypevr
diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
index 0aab45f4992..b0207146e8c 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -6921,6 +6921,15 @@ line debug info sections.  This will result in much more compact line number
 tables, and hence is desirable if it works.
 @end defmac
 
+@defmac DWARF2_ASM_VIEW_DEBUG_INFO
+Define this macro to be a nonzero value if the assembler supports view
+assignment and verification in @code{.loc}.  If it does not, but the
+user enables location views, the compiler may have to fallback to
+internal line number tables.
+@end defmac
+
+@hook TARGET_RESET_LOCATION_VIEW
+
 @hook TARGET_WANT_DEBUG_PUB_SECTIONS
 
 @hook TARGET_DELAY_SCHED2
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index 984df9fe4e9..4e2bf3b4c88 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -2957,6 +2957,37 @@ struct GTY(()) dw_line_info_table {
   vec<dw_line_info_entry, va_gc> *entries;
 };
 
+/* If we're keep track of location views and their reset points, and
+   INSN is a reset point (i.e., it necessarily advances the PC), mark
+   the next view in TABLE as reset.  */
+
+static void
+maybe_reset_location_view (rtx_insn *insn, dw_line_info_table *table)
+{
+  if (!debug_internal_reset_location_views)
+    return;
+
+  /* Maybe turn (part of?) this test into a default target hook.  */
+  int reset = 0;
+
+  if (targetm.reset_location_view)
+    reset = targetm.reset_location_view (insn);
+
+  if (reset)
+    ;
+  else if (JUMP_TABLE_DATA_P (insn))
+    reset = 1;
+  else if (GET_CODE (insn) == USE
+	   || GET_CODE (insn) == CLOBBER
+	   || GET_CODE (insn) == ASM_INPUT
+	   || asm_noperands (insn) >= 0)
+    ;
+  else if (get_attr_min_length (insn) > 0)
+    reset = 1;
+
+  if (reset > 0)
+    RESET_NEXT_VIEW (table->view);
+}
 
 /* Each DIE attribute has a field specifying the attribute kind,
    a link to the next attribute in the chain, and an attribute value.
@@ -3164,6 +3195,31 @@ skeleton_chain_node;
 #endif
 #endif
 
+/* Return true if GCC configure detected assembler support for .loc.  */
+
+bool
+dwarf2out_default_as_loc_support (void)
+{
+  return DWARF2_ASM_LINE_DEBUG_INFO;
+#if (GCC_VERSION >= 3000)
+# undef DWARF2_ASM_LINE_DEBUG_INFO
+# pragma GCC poison DWARF2_ASM_LINE_DEBUG_INFO
+#endif
+}
+
+/* Return true if GCC configure detected assembler support for views
+   in .loc directives.  */
+
+bool
+dwarf2out_default_as_locview_support (void)
+{
+  return DWARF2_ASM_VIEW_DEBUG_INFO;
+#if (GCC_VERSION >= 3000)
+# undef DWARF2_ASM_VIEW_DEBUG_INFO
+# pragma GCC poison DWARF2_ASM_VIEW_DEBUG_INFO
+#endif
+}
+
 /* A bit is set in ZERO_VIEW_P if we are using the assembler-supported
    view computation, and it refers to a view identifier for which we
    will not emit a label because it is known to map to a view number
@@ -3215,9 +3271,9 @@ static GTY(()) bitmap zero_view_p;
 static bool
 output_asm_line_debug_info (void)
 {
-  return (DWARF2_ASM_VIEW_DEBUG_INFO
-	  || (DWARF2_ASM_LINE_DEBUG_INFO
-	      && !debug_variable_location_views));
+  return (dwarf2out_as_loc_support
+	  && (dwarf2out_as_locview_support
+	      || !debug_variable_location_views));
 }
 
 /* Minimum line offset in a special line info. opcode.
@@ -9950,28 +10006,31 @@ dwarf2out_maybe_output_loclist_view_pair (dw_loc_list_ref curr)
 #ifdef DW_LLE_view_pair
   dw2_asm_output_data (1, DW_LLE_view_pair, "DW_LLE_view_pair");
 
-# if DWARF2_ASM_VIEW_DEBUG_INFO
-  if (ZERO_VIEW_P (curr->vbegin))
-    dw2_asm_output_data_uleb128 (0, "Location view begin");
-  else
+  if (dwarf2out_as_locview_support)
     {
-      char label[MAX_ARTIFICIAL_LABEL_BYTES];
-      ASM_GENERATE_INTERNAL_LABEL (label, "LVU", curr->vbegin);
-      dw2_asm_output_symname_uleb128 (label, "Location view begin");
-    }
+      if (ZERO_VIEW_P (curr->vbegin))
+	dw2_asm_output_data_uleb128 (0, "Location view begin");
+      else
+	{
+	  char label[MAX_ARTIFICIAL_LABEL_BYTES];
+	  ASM_GENERATE_INTERNAL_LABEL (label, "LVU", curr->vbegin);
+	  dw2_asm_output_symname_uleb128 (label, "Location view begin");
+	}
 
-  if (ZERO_VIEW_P (curr->vend))
-    dw2_asm_output_data_uleb128 (0, "Location view end");
+      if (ZERO_VIEW_P (curr->vend))
+	dw2_asm_output_data_uleb128 (0, "Location view end");
+      else
+	{
+	  char label[MAX_ARTIFICIAL_LABEL_BYTES];
+	  ASM_GENERATE_INTERNAL_LABEL (label, "LVU", curr->vend);
+	  dw2_asm_output_symname_uleb128 (label, "Location view end");
+	}
+    }
   else
     {
-      char label[MAX_ARTIFICIAL_LABEL_BYTES];
-      ASM_GENERATE_INTERNAL_LABEL (label, "LVU", curr->vend);
-      dw2_asm_output_symname_uleb128 (label, "Location view end");
+      dw2_asm_output_data_uleb128 (curr->vbegin, "Location view begin");
+      dw2_asm_output_data_uleb128 (curr->vend, "Location view end");
     }
-# else /* !DWARF2_ASM_VIEW_DEBUG_INFO */
-  dw2_asm_output_data_uleb128 (curr->vbegin, "Location view begin");
-  dw2_asm_output_data_uleb128 (curr->vend, "Location view end");
-# endif /* DWARF2_ASM_VIEW_DEBUG_INFO */
 #endif /* DW_LLE_view_pair */
 
   return;
@@ -10001,40 +10060,43 @@ output_loc_list (dw_loc_list_ref list_head)
 	  vcount++;
 
 	  /* ?? dwarf_split_debug_info?  */
-#if DWARF2_ASM_VIEW_DEBUG_INFO
-	  char label[MAX_ARTIFICIAL_LABEL_BYTES];
-
-	  if (!ZERO_VIEW_P (curr->vbegin))
+	  if (dwarf2out_as_locview_support)
 	    {
-	      ASM_GENERATE_INTERNAL_LABEL (label, "LVU", curr->vbegin);
-	      dw2_asm_output_symname_uleb128 (label,
-					      "View list begin (%s)",
-					      list_head->vl_symbol);
+	      char label[MAX_ARTIFICIAL_LABEL_BYTES];
+
+	      if (!ZERO_VIEW_P (curr->vbegin))
+		{
+		  ASM_GENERATE_INTERNAL_LABEL (label, "LVU", curr->vbegin);
+		  dw2_asm_output_symname_uleb128 (label,
+						  "View list begin (%s)",
+						  list_head->vl_symbol);
+		}
+	      else
+		dw2_asm_output_data_uleb128 (0,
+					     "View list begin (%s)",
+					     list_head->vl_symbol);
+
+	      if (!ZERO_VIEW_P (curr->vend))
+		{
+		  ASM_GENERATE_INTERNAL_LABEL (label, "LVU", curr->vend);
+		  dw2_asm_output_symname_uleb128 (label,
+						  "View list end (%s)",
+						  list_head->vl_symbol);
+		}
+	      else
+		dw2_asm_output_data_uleb128 (0,
+					     "View list end (%s)",
+					     list_head->vl_symbol);
 	    }
 	  else
-	    dw2_asm_output_data_uleb128 (0,
-					 "View list begin (%s)",
-					 list_head->vl_symbol);
-
-	  if (!ZERO_VIEW_P (curr->vend))
 	    {
-	      ASM_GENERATE_INTERNAL_LABEL (label, "LVU", curr->vend);
-	      dw2_asm_output_symname_uleb128 (label,
-					      "View list end (%s)",
-					      list_head->vl_symbol);
+	      dw2_asm_output_data_uleb128 (curr->vbegin,
+					   "View list begin (%s)",
+					   list_head->vl_symbol);
+	      dw2_asm_output_data_uleb128 (curr->vend,
+					   "View list end (%s)",
+					   list_head->vl_symbol);
 	    }
-	  else
-	    dw2_asm_output_data_uleb128 (0,
-					 "View list end (%s)",
-					 list_head->vl_symbol);
-#else /* !DWARF2_ASM_VIEW_DEBUG_INFO */
-	  dw2_asm_output_data_uleb128 (curr->vbegin,
-				       "View list begin (%s)",
-				       list_head->vl_symbol);
-	  dw2_asm_output_data_uleb128 (curr->vend,
-				       "View list end (%s)",
-				       list_head->vl_symbol);
-#endif
 	}
     }
 
@@ -23721,11 +23783,14 @@ add_high_low_attributes (tree stmt, dw_die_ref die)
     {
       inline_entry_data *ied = *iedp;
       gcc_assert (MAY_HAVE_DEBUG_MARKER_INSNS);
+      gcc_assert (debug_inline_points);
       gcc_assert (inlined_function_outer_scope_p (stmt));
+
       ASM_GENERATE_INTERNAL_LABEL (label, ied->label_pfx, ied->label_num);
       add_AT_lbl_id (die, DW_AT_entry_pc, label);
 
-      if (debug_variable_location_views && !ZERO_VIEW_P (ied->view))
+      if (debug_variable_location_views && !ZERO_VIEW_P (ied->view)
+	  && !dwarf_strict)
 	{
 	  if (!output_asm_line_debug_info ())
 	    add_AT_unsigned (die, DW_AT_GNU_entry_view, ied->view);
@@ -23756,7 +23821,7 @@ add_high_low_attributes (tree stmt, dw_die_ref die)
       dw_die_ref pdie;
       dw_attr_node *attr = NULL;
 
-      if (!MAY_HAVE_DEBUG_MARKER_INSNS && inlined_function_outer_scope_p (stmt))
+      if (!debug_inline_points && inlined_function_outer_scope_p (stmt))
 	{
 	  ASM_GENERATE_INTERNAL_LABEL (label, BLOCK_BEGIN_LABEL,
 				       BLOCK_NUMBER (stmt));
@@ -23921,7 +23986,7 @@ gen_inlined_subroutine_die (tree stmt, dw_die_ref context_die)
       dw_die_ref subr_die
 	= new_die (DW_TAG_inlined_subroutine, context_die, stmt);
 
-      if (call_arg_locations || MAY_HAVE_DEBUG_MARKER_INSNS)
+      if (call_arg_locations || debug_inline_points)
 	BLOCK_DIE (stmt) = subr_die;
       add_abstract_origin_attribute (subr_die, decl);
       if (TREE_ASM_WRITTEN (stmt))
@@ -26906,7 +26971,7 @@ dwarf2out_var_location (rtx_insn *loc_note)
     {
       if (CALL_P (loc_note))
 	{
-	  RESET_NEXT_VIEW (cur_line_info_table->view);
+	  maybe_reset_location_view (loc_note, cur_line_info_table);
 	  call_site_count++;
 	  if (SIBLING_CALL_P (loc_note))
 	    tail_call_site_count++;
@@ -26942,15 +27007,8 @@ dwarf2out_var_location (rtx_insn *loc_note)
 	}
       else if (!debug_variable_location_views)
 	gcc_unreachable ();
-      else if (JUMP_TABLE_DATA_P (loc_note))
-	RESET_NEXT_VIEW (cur_line_info_table->view);
-      else if (GET_CODE (loc_note) == USE
-	       || GET_CODE (loc_note) == CLOBBER
-	       || GET_CODE (loc_note) == ASM_INPUT
-	       || asm_noperands (loc_note) >= 0)
-	;
-      else if (get_attr_min_length (loc_note) > 0)
-	RESET_NEXT_VIEW (cur_line_info_table->view);
+      else
+	maybe_reset_location_view (loc_note, cur_line_info_table);
 
       return;
     }
@@ -27219,6 +27277,8 @@ block_within_block_p (tree block, tree outer, bool bothways)
 static void
 dwarf2out_inline_entry (tree block)
 {
+  gcc_assert (debug_inline_points);
+
   /* If we can't represent it, don't bother.  */
   if (!(dwarf_version >= 3 || !dwarf_strict))
     return;
@@ -28233,7 +28293,7 @@ init_sections_and_labels (bool early_lto_debug)
       debug_str_section = get_section (DEBUG_LTO_STR_SECTION,
 				       DEBUG_STR_SECTION_FLAGS
 				       | SECTION_EXCLUDE, NULL);
-      if (!dwarf_split_debug_info && !DWARF2_ASM_LINE_DEBUG_INFO)
+      if (!dwarf_split_debug_info && !dwarf2out_as_loc_support)
 	debug_line_str_section
 	  = get_section (DEBUG_LTO_LINE_STR_SECTION,
 			 DEBUG_STR_SECTION_FLAGS | SECTION_EXCLUDE, NULL);
@@ -31468,7 +31528,7 @@ dwarf2out_early_finish (const char *filename)
 
   /* When emitting DWARF5 .debug_line_str, move DW_AT_name and
      DW_AT_comp_dir into .debug_line_str section.  */
-  if (!DWARF2_ASM_LINE_DEBUG_INFO
+  if (!dwarf2out_as_loc_support
       && dwarf_version >= 5
       && DWARF5_USE_DEBUG_LINE_STR)
     {
diff --git a/gcc/hooks.c b/gcc/hooks.c
index 61719606a36..780cc1e0863 100644
--- a/gcc/hooks.c
+++ b/gcc/hooks.c
@@ -236,6 +236,12 @@ hook_int_rtx_1 (rtx)
 }
 
 int
+hook_int_rtx_insn_0 (rtx_insn *)
+{
+  return 0;
+}
+
+int
 hook_int_rtx_insn_unreachable (rtx_insn *)
 {
   gcc_unreachable ();
diff --git a/gcc/hooks.h b/gcc/hooks.h
index 8caedd429a6..0ed5b952b48 100644
--- a/gcc/hooks.h
+++ b/gcc/hooks.h
@@ -93,6 +93,7 @@ extern int hook_int_const_tree_0 (const_tree);
 extern int hook_int_const_tree_const_tree_1 (const_tree, const_tree);
 extern int hook_int_rtx_0 (rtx);
 extern int hook_int_rtx_1 (rtx);
+extern int hook_int_rtx_insn_0 (rtx_insn *);
 extern int hook_int_rtx_insn_unreachable (rtx_insn *);
 extern int hook_int_rtx_bool_0 (rtx, bool);
 extern int hook_int_rtx_mode_as_bool_0 (rtx, machine_mode, addr_space_t,
diff --git a/gcc/target.def b/gcc/target.def
index aeb41df1945..c5b2a1e7e71 100644
--- a/gcc/target.def
+++ b/gcc/target.def
@@ -6447,6 +6447,23 @@ This will suppress generation of the normal debug frame unwind information.",
  enum unwind_info_type, (void),
  default_debug_unwind_info)
 
+DEFHOOK
+(reset_location_view, "\
+This hook, if defined, enables -ginternal-reset-location-views, and\n\
+uses its result to override cases in which the estimated min insn\n\
+length might be nonzero even when a PC advance (i.e., a view reset)\n\
+cannot be taken for granted.\n\
+\n\
+If the hook is defined, it must return a positive value to indicate\n\
+the insn definitely advances the PC, and so the view number can be\n\
+safely assumed to be reset; a negative value to mean the insn\n\
+definitely does not advance the PC, and os the view number must not\n\
+be reset; or zero to decide based on the estimated insn length.\n\
+\n\
+If insn length is to be regarded as reliable, set the hook to\n\
+@code{hook_int_rtx_insn_0}.",
+ int, (rtx_insn *), NULL)
+
 /* The code parameter should be of type enum rtx_code but this is not
    defined at this time.  */
 DEFHOOK
diff --git a/gcc/toplev.c b/gcc/toplev.c
index 23db0636fc7..b066bcc7229 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -1558,13 +1558,23 @@ process_options (void)
 	     || write_symbols == VMS_AND_DWARF2_DEBUG)
 	 && !(flag_selective_scheduling || flag_selective_scheduling2));
 
+  if (dwarf2out_as_loc_support == AUTODETECT_VALUE)
+    dwarf2out_as_loc_support
+      = dwarf2out_default_as_loc_support ();
+  if (dwarf2out_as_locview_support == AUTODETECT_VALUE)
+    dwarf2out_as_locview_support
+      = dwarf2out_default_as_locview_support ();
+
   if (debug_variable_location_views == AUTODETECT_VALUE)
     {
-      debug_variable_location_views = flag_var_tracking
-	&& debug_info_level >= DINFO_LEVEL_NORMAL
-	&& (write_symbols == DWARF2_DEBUG
-	    || write_symbols == VMS_AND_DWARF2_DEBUG)
-	&& !dwarf_strict;
+      debug_variable_location_views
+	= (flag_var_tracking
+	   && debug_info_level >= DINFO_LEVEL_NORMAL
+	   && (write_symbols == DWARF2_DEBUG
+	       || write_symbols == VMS_AND_DWARF2_DEBUG)
+	   && !dwarf_strict
+	   && dwarf2out_as_loc_support
+	   && dwarf2out_as_locview_support);
     }
   else if (debug_variable_location_views == -1 && dwarf_version != 5)
     {
@@ -1574,6 +1584,31 @@ process_options (void)
       debug_variable_location_views = 1;
     }
 
+  if (debug_internal_reset_location_views == 2)
+    {
+      debug_internal_reset_location_views
+	= (debug_variable_location_views
+	   && targetm.reset_location_view);
+    }
+  else if (debug_internal_reset_location_views
+	   && !debug_variable_location_views)
+    {
+      warning_at (UNKNOWN_LOCATION, 0,
+		  "-ginternal-reset-location-views is forced disabled "
+		  "without -gvariable-location-views");
+      debug_internal_reset_location_views = 0;
+    }
+
+  if (debug_inline_points == AUTODETECT_VALUE)
+    debug_inline_points = debug_variable_location_views;
+  else if (debug_inline_points && !debug_nonbind_markers_p)
+    {
+      warning_at (UNKNOWN_LOCATION, 0,
+		  "-ginline-points is forced disabled without "
+		  "-gstatement-frontiers");
+      debug_inline_points = 0;
+    }
+
   if (flag_tree_cselim == AUTODETECT_VALUE)
     {
       if (HAVE_conditional_move)
diff --git a/gcc/tree-inline.c b/gcc/tree-inline.c
index 7f9ec770e19..811829e8529 100644
--- a/gcc/tree-inline.c
+++ b/gcc/tree-inline.c
@@ -4605,7 +4605,7 @@ expand_call_inline (basic_block bb, gimple *stmt, copy_body_data *id)
 			GSI_NEW_STMT);
     }
   initialize_inlined_parameters (id, stmt, fn, bb);
-  if (debug_nonbind_markers_p && id->block
+  if (debug_nonbind_markers_p && debug_inline_points && id->block
       && inlined_function_outer_scope_p (id->block))
     {
       gimple_stmt_iterator si = gsi_last_bb (bb);
diff --git a/gcc/tree-ssa-live.c b/gcc/tree-ssa-live.c
index 26da31f74cb..62bb3c5de65 100644
--- a/gcc/tree-ssa-live.c
+++ b/gcc/tree-ssa-live.c
@@ -522,7 +522,7 @@ remove_unused_scope_block_p (tree scope, bool in_ctor_dtor_block)
      unused = false;
    /* Preserve the block, it is referenced by at least the inline
       entry point marker.  */
-   else if (debug_nonbind_markers_p
+   else if (debug_inline_points
 	    && inlined_function_outer_scope_p (scope))
      unused = false;
    /* Innermost blocks with no live variables nor statements can be always
@@ -558,7 +558,7 @@ remove_unused_scope_block_p (tree scope, bool in_ctor_dtor_block)
       with block_ultimate_origin being set to FUNCTION_DECL and
       DECL_SOURCE_LOCATION set, unless they expand to nothing...  But
       see above for the case of statement frontiers.  */
-   else if (!debug_nonbind_markers_p
+   else if (!debug_inline_points
 	    && inlined_function_outer_scope_p (scope))
      unused = false;
    else