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[PATCH] Remove unnecessary and troublesome sparc constraint.
- From: David Miller <davem at davemloft dot net>
- To: gcc-patches at gcc dot gnu dot org
- Date: Thu, 25 Oct 2012 18:19:58 -0400 (EDT)
- Subject: [PATCH] Remove unnecessary and troublesome sparc constraint.
This was discovered while playing around with LRA, but of course
I regstrapped this using the existing reload pass.
Constraint "U" is a register constraint, that accepts either a
pseudo or an even numbered hard register. But it is bogus, and
in fact unnecessary.
First, it isn't marked as a "define_register_constraint" so it
doesn't properly represent a register class.
Second, and more importantly in my opinion, this check is not the job
of a constraint. Any piece of code in the compiler (be it in IRA,
LRA, or traditional reload) which would assign a hard register will do
so correctly because HARD_REGNO_MODE_OK() ensures that this
requirement is met for 64-bit values when generating 32-bit code.
Therefore remove "U" and just use plain "r".
FWIW the trouble this caused with LRA is that we had an expression
like:
(set (mem:DI %sfp -8) (reg:DI PSEUDO))
and with optimizations disabled LRA allocated a spill stack slot and
thus turned this into:
(set (mem:DI %sfp -8) (mem:DI %sfp -32))
The originally matched alternative of *movdi_insn_sp32 used constraints
"T" for output (8-byte aligned memory) and this register constraint "U"
for input.
However in the new form with the pseudo replaced with a spill slot,
LRA can't tell that this instruction can be reloaded. This is because
"U" doesn't evaluate to a register class when LRA makes the check
using REG_CLASS_FROM_CONSTRAINT, instead it gets NO_REGS, and it
therefore won't set "winreg" and we'll abort.
Committed to master.
* config/sparc/constraints.md ("U"): Delete.
* config/sparc/sparc.md: Use 'r' constraint instead of 'U'.
* config/sparc/sync.md: Likewise.
---
gcc/ChangeLog | 8 +++++++-
gcc/config/sparc/constraints.md | 9 ---------
gcc/config/sparc/sparc.md | 16 ++++++++--------
gcc/config/sparc/sync.md | 4 ++--
4 files changed, 17 insertions(+), 20 deletions(-)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 47a7a4e..d6751b1 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,7 +1,13 @@
+2012-10-25 David S. Miller <davem@davemloft.net>
+
+ * config/sparc/constraints.md ("U"): Delete.
+ * config/sparc/sparc.md: Use 'r' constraint instead of 'U'.
+ * config/sparc/sync.md: Likewise.
+
2012-10-25 Lawrence Crowl <crowl@google.com>
* hash-table.h: Add usage documentation.
- (template struct typed_free_remove): Clarify documentation.
+ (template struct typed_free_remove): Clarify documentation.
Rename template parameter.
(struct typed_noop_remove): Likewise.
(descriptor concept): Change typedef T to value_type.
diff --git a/gcc/config/sparc/constraints.md b/gcc/config/sparc/constraints.md
index ffe5304..1d99d4b 100644
--- a/gcc/config/sparc/constraints.md
+++ b/gcc/config/sparc/constraints.md
@@ -138,15 +138,6 @@
(match_code "mem")
(match_test "memory_ok_for_ldd (op)")))
-;; Not needed in 64-bit mode
-(define_constraint "U"
- "Pseudo-register or hard even-numbered integer register"
- (and (match_test "TARGET_ARCH32")
- (match_code "reg")
- (ior (match_test "REGNO (op) < FIRST_PSEUDO_REGISTER")
- (not (match_test "reload_in_progress && reg_renumber [REGNO (op)] < 0")))
- (match_test "register_ok_for_ldd (op)")))
-
;; Equivalent to 'T' but available in 64-bit mode
(define_memory_constraint "W"
"Memory reference for 'e' constraint floating-point register"
diff --git a/gcc/config/sparc/sparc.md b/gcc/config/sparc/sparc.md
index f604f46..4a44078 100644
--- a/gcc/config/sparc/sparc.md
+++ b/gcc/config/sparc/sparc.md
@@ -1595,9 +1595,9 @@
(define_insn "*movdi_insn_sp32"
[(set (match_operand:DI 0 "nonimmediate_operand"
- "=T,o,T,U,o,r,r,r,?T,?*f,?*f,?o,?*e,?*e, r,?*f,?*e,?W,b,b")
+ "=T,o,T,r,o,r,r,r,?T,?*f,?*f,?o,?*e,?*e, r,?*f,?*e,?W,b,b")
(match_operand:DI 1 "input_operand"
- " J,J,U,T,r,o,i,r,*f, T, o,*f, *e, *e,?*f, r, W,*e,J,P"))]
+ " J,J,r,T,r,o,i,r,*f, T, o,*f, *e, *e,?*f, r, W,*e,J,P"))]
"! TARGET_ARCH64
&& (register_operand (operands[0], DImode)
|| register_or_zero_operand (operands[1], DImode))"
@@ -2302,8 +2302,8 @@
})
(define_insn "*movdf_insn_sp32"
- [(set (match_operand:DF 0 "nonimmediate_operand" "=b,b,e,e,*r, f, e,T,W,U,T, f, *r, o,o")
- (match_operand:DF 1 "input_operand" "G,C,e,e, f,*r,W#F,G,e,T,U,o#F,*roF,*rG,f"))]
+ [(set (match_operand:DF 0 "nonimmediate_operand" "=b,b,e,e,*r, f, e,T,W,r,T, f, *r, o,o")
+ (match_operand:DF 1 "input_operand" "G,C,e,e, f,*r,W#F,G,e,T,r,o#F,*roF,*rG,f"))]
"! TARGET_ARCH64
&& (register_operand (operands[0], DFmode)
|| register_or_zero_or_all_ones_operand (operands[1], DFmode))"
@@ -2541,8 +2541,8 @@
})
(define_insn "*movtf_insn_sp32"
- [(set (match_operand:TF 0 "nonimmediate_operand" "=b, e,o, o,U, r")
- (match_operand:TF 1 "input_operand" " G,oe,e,rGU,o,roG"))]
+ [(set (match_operand:TF 0 "nonimmediate_operand" "=b, e,o, o,r, r")
+ (match_operand:TF 1 "input_operand" " G,oe,e,rG,o,roG"))]
"! TARGET_ARCH64
&& (register_operand (operands[0], TFmode)
|| register_or_zero_operand (operands[1], TFmode))"
@@ -7911,8 +7911,8 @@
(set_attr "cpu_feature" "vis,vis,vis,*,*,*,*,*,vis3,vis3,*")])
(define_insn "*mov<VM64:mode>_insn_sp32"
- [(set (match_operand:VM64 0 "nonimmediate_operand" "=e,e,e,*r, f,e,m,m,U,T, o,*r")
- (match_operand:VM64 1 "input_operand" "Y,C,e, f,*r,m,e,Y,T,U,*r,*r"))]
+ [(set (match_operand:VM64 0 "nonimmediate_operand" "=e,e,e,*r, f,e,m,m,r,T, o,*r")
+ (match_operand:VM64 1 "input_operand" "Y,C,e, f,*r,m,e,Y,T,r,*r,*r"))]
"TARGET_VIS
&& ! TARGET_ARCH64
&& (register_operand (operands[0], <VM64:MODE>mode)
diff --git a/gcc/config/sparc/sync.md b/gcc/config/sparc/sync.md
index d11f663..302cd74 100644
--- a/gcc/config/sparc/sync.md
+++ b/gcc/config/sparc/sync.md
@@ -115,7 +115,7 @@
})
(define_insn "atomic_loaddi_1"
- [(set (match_operand:DI 0 "register_operand" "=U,?*f")
+ [(set (match_operand:DI 0 "register_operand" "=r,?*f")
(unspec:DI [(match_operand:DI 1 "memory_operand" "m,m")]
UNSPEC_ATOMIC))]
"!TARGET_ARCH64"
@@ -144,7 +144,7 @@
(define_insn "atomic_storedi_1"
[(set (match_operand:DI 0 "memory_operand" "=m,m,m")
(unspec:DI
- [(match_operand:DI 1 "register_or_v9_zero_operand" "J,U,?*f")]
+ [(match_operand:DI 1 "register_or_v9_zero_operand" "J,r,?*f")]
UNSPEC_ATOMIC))]
"!TARGET_ARCH64"
"@
--
1.7.12.2.dirty