1; RUN: llc -march=ppc32 -mtriple=powerpc-unknown-linux-gnu -mattr=+altivec < %s | FileCheck %s 2 3;; This test ensures that MergeConsecutiveStores does not attempt to 4;; merge stores or loads when doing so would result in unaligned 5;; memory operations (unless the target supports those, e.g. X86). 6 7;; This issue happen in other situations for other targets, but PPC 8;; with Altivec extensions was chosen for the test because it does not 9;; support unaligned access with AltiVec instructions. If the 4 10;; load/stores get merged to an v4i32 vector type severely bad code 11;; gets generated: it painstakingly copies the values to a temporary 12;; location on the stack, with vector ops, in order to then use 13;; integer ops to load from the temporary stack location and store to 14;; the final location. Yuck! 15 16%struct.X = type { i32, i32, i32, i32 } 17 18@fx = common global %struct.X zeroinitializer, align 4 19@fy = common global %struct.X zeroinitializer, align 4 20 21;; In this test case, lvx and stvx instructions should NOT be 22;; generated, as the alignment is not sufficient for it to be 23;; worthwhile. 24 25;; CHECK-LABEL: f: 26;; CHECK: lwzu 27;; CHECK-NEXT: lwz 28;; CHECK-NEXT: lwz 29;; CHECK-NEXT: lwz 30;; CHECK-NEXT: stwu 31;; CHECK-NEXT: stw 32;; CHECK-NEXT: stw 33;; CHECK-NEXT: stw 34;; CHECK-NEXT: blr 35define void @f() { 36entry: 37 %0 = load i32, i32* getelementptr inbounds (%struct.X, %struct.X* @fx, i32 0, i32 0), align 4 38 %1 = load i32, i32* getelementptr inbounds (%struct.X, %struct.X* @fx, i32 0, i32 1), align 4 39 %2 = load i32, i32* getelementptr inbounds (%struct.X, %struct.X* @fx, i32 0, i32 2), align 4 40 %3 = load i32, i32* getelementptr inbounds (%struct.X, %struct.X* @fx, i32 0, i32 3), align 4 41 store i32 %0, i32* getelementptr inbounds (%struct.X, %struct.X* @fy, i32 0, i32 0), align 4 42 store i32 %1, i32* getelementptr inbounds (%struct.X, %struct.X* @fy, i32 0, i32 1), align 4 43 store i32 %2, i32* getelementptr inbounds (%struct.X, %struct.X* @fy, i32 0, i32 2), align 4 44 store i32 %3, i32* getelementptr inbounds (%struct.X, %struct.X* @fy, i32 0, i32 3), align 4 45 ret void 46} 47 48@gx = common global %struct.X zeroinitializer, align 16 49@gy = common global %struct.X zeroinitializer, align 16 50 51;; In this test, lvx and stvx instructions SHOULD be generated, as 52;; the 16-byte alignment of the new load/store is acceptable. 53;; CHECK-LABEL: g: 54;; CHECK: lvx 55;; CHECK: stvx 56;; CHECK: blr 57define void @g() { 58entry: 59 %0 = load i32, i32* getelementptr inbounds (%struct.X, %struct.X* @fx, i32 0, i32 0), align 16 60 %1 = load i32, i32* getelementptr inbounds (%struct.X, %struct.X* @fx, i32 0, i32 1), align 4 61 %2 = load i32, i32* getelementptr inbounds (%struct.X, %struct.X* @fx, i32 0, i32 2), align 4 62 %3 = load i32, i32* getelementptr inbounds (%struct.X, %struct.X* @fx, i32 0, i32 3), align 4 63 store i32 %0, i32* getelementptr inbounds (%struct.X, %struct.X* @fy, i32 0, i32 0), align 16 64 store i32 %1, i32* getelementptr inbounds (%struct.X, %struct.X* @fy, i32 0, i32 1), align 4 65 store i32 %2, i32* getelementptr inbounds (%struct.X, %struct.X* @fy, i32 0, i32 2), align 4 66 store i32 %3, i32* getelementptr inbounds (%struct.X, %struct.X* @fy, i32 0, i32 3), align 4 67 ret void 68} 69